drm/radeon: check the return value of uvd_v1_0_start in uvd_v1_0_init

No need to try the ring tests if starting the UVD block failed.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>

drivers/gpu/drm/radeon/uvd_v1_0.c

@@ -85,7 +85,9 @@ int uvd_v1_0_init(struct radeon_device *rdev)
 	/* raise clocks while booting up the VCPU */
 	radeon_set_uvd_clocks(rdev, 53300, 40000);
 
-	uvd_v1_0_start(rdev);
+	r = uvd_v1_0_start(rdev);
+	if (r)
+		goto done;
 
 	ring->ready = true;
 	r = radeon_ring_test(rdev, R600_RING_TYPE_UVD_INDEX, ring);