drm/amdgpu: fix uninitialized variable warning for jpeg_v4

Clear warning that using uninitialized variable r.
Signed-off-by: Tim Huang <Tim.Huang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/jpeg_v4_0_5.c

@@ -187,7 +187,7 @@ static int jpeg_v4_0_5_hw_init(void *handle)
 {
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 	struct amdgpu_ring *ring;
-	int r, i;
+	int i, r = 0;
 
 	// TODO: Enable ring test with DPG support
 	if (adev->pg_flags & AMD_PG_SUPPORT_JPEG_DPG) {