The size of fw_name is increased to ensure that it can accommodate
the maximum possible size of the string being written into it.

Fixes the below with gcc W=1:
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c: In function ‘gfx_v9_0_early_init’:
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1255:52: warning: ‘%s’ directive output may be truncated writing up to 29 bytes into a region of size 23 [-Wformat-truncation=]
 1255 |         snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_pfp.bin", chip_name);
      |                                                    ^~
......
 1393 |                 r = gfx_v9_0_init_cp_gfx_microcode(adev, ucode_prefix);
      |                                                          ~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1255:9: note: ‘snprintf’ output between 16 and 45 bytes into a destination of size 30
 1255 |         snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_pfp.bin", chip_name);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1261:52: warning: ‘%s’ directive output may be truncated writing up to 29 bytes into a region of size 23 [-Wformat-truncation=]
 1261 |         snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_me.bin", chip_name);
      |                                                    ^~
......
 1393 |                 r = gfx_v9_0_init_cp_gfx_microcode(adev, ucode_prefix);
      |                                                          ~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1261:9: note: ‘snprintf’ output between 15 and 44 bytes into a destination of size 30
 1261 |         snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_me.bin", chip_name);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1267:52: warning: ‘%s’ directive output may be truncated writing up to 29 bytes into a region of size 23 [-Wformat-truncation=]
 1267 |         snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_ce.bin", chip_name);
      |                                                    ^~
......
 1393 |                 r = gfx_v9_0_init_cp_gfx_microcode(adev, ucode_prefix);
      |                                                          ~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1267:9: note: ‘snprintf’ output between 15 and 44 bytes into a destination of size 30
 1267 |         snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_ce.bin", chip_name);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1303:60: warning: ‘%s’ directive output may be truncated writing up to 29 bytes into a region of size 23 [-Wformat-truncation=]
 1303 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_rlc_am4.bin", chip_name);
      |                                                            ^~
......
 1398 |         r = gfx_v9_0_init_rlc_microcode(adev, ucode_prefix);
      |                                               ~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1303:17: note: ‘snprintf’ output between 20 and 49 bytes into a destination of size 30
 1303 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_rlc_am4.bin", chip_name);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1309:60: warning: ‘%s’ directive output may be truncated writing up to 29 bytes into a region of size 23 [-Wformat-truncation=]
 1309 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_kicker_rlc.bin", chip_name);
      |                                                            ^~
......
 1398 |         r = gfx_v9_0_init_rlc_microcode(adev, ucode_prefix);
      |                                               ~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1309:17: note: ‘snprintf’ output between 23 and 52 bytes into a destination of size 30
 1309 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_kicker_rlc.bin", chip_name);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1311:60: warning: ‘%s’ directive output may be truncated writing up to 29 bytes into a region of size 23 [-Wformat-truncation=]
 1311 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_rlc.bin", chip_name);
      |                                                            ^~
......
 1398 |         r = gfx_v9_0_init_rlc_microcode(adev, ucode_prefix);
      |                                               ~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1311:17: note: ‘snprintf’ output between 16 and 45 bytes into a destination of size 30
 1311 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_rlc.bin", chip_name);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1344:60: warning: ‘%s’ directive output may be truncated writing up to 29 bytes into a region of size 23 [-Wformat-truncation=]
 1344 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_sjt_mec.bin", chip_name);
      |                                                            ^~
......
 1402 |         r = gfx_v9_0_init_cp_compute_microcode(adev, ucode_prefix);
      |                                                      ~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1344:17: note: ‘snprintf’ output between 20 and 49 bytes into a destination of size 30
 1344 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_sjt_mec.bin", chip_name);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1346:60: warning: ‘%s’ directive output may be truncated writing up to 29 bytes into a region of size 23 [-Wformat-truncation=]
 1346 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_mec.bin", chip_name);
      |                                                            ^~
......
 1402 |         r = gfx_v9_0_init_cp_compute_microcode(adev, ucode_prefix);
      |                                                      ~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1346:17: note: ‘snprintf’ output between 16 and 45 bytes into a destination of size 30
 1346 |                 snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_mec.bin", chip_name);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1356:68: warning: ‘%s’ directive output may be truncated writing up to 29 bytes into a region of size 23 [-Wformat-truncation=]
 1356 |                         snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_sjt_mec2.bin", chip_name);
      |                                                                    ^~
......
 1402 |         r = gfx_v9_0_init_cp_compute_microcode(adev, ucode_prefix);
      |                                                      ~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1356:25: note: ‘snprintf’ output between 21 and 50 bytes into a destination of size 30
 1356 |                         snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_sjt_mec2.bin", chip_name);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1358:68: warning: ‘%s’ directive output may be truncated writing up to 29 bytes into a region of size 23 [-Wformat-truncation=]
 1358 |                         snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_mec2.bin", chip_name);
      |                                                                    ^~
......
 1402 |         r = gfx_v9_0_init_cp_compute_microcode(adev, ucode_prefix);
      |                                                      ~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:1358:25: note: ‘snprintf’ output between 17 and 46 bytes into a destination of size 30
 1358 |                         snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_mec2.bin", chip_name);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Suggested-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>