drm/amdgpu: Fix unsigned comparison with zero in gmc_v9_0_process_interrupt()

Smatch warns:
	drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c:579:
	unsigned 'xcc_id' is never less than zero.

gfx_v9_4_3_ih_to_xcc_inst() returns negative numbers as well.
Fix this by changing type of xcc_id to int.

Fixes: 98b2e9ca ("drm/amdgpu: correct the vmhub index when page fault occurs")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

@@ -557,8 +557,8 @@ static int gmc_v9_0_process_interrupt(struct amdgpu_device *adev,
 	const char *hub_name;
 	u64 addr;
 	uint32_t cam_index = 0;
-	int ret;
-	uint32_t node_id, xcc_id = 0;
+	int ret, xcc_id = 0;
+	uint32_t node_id;
 
 	node_id = entry->node_id;