amdgpu/uvd: get ring reference from rq scheduler

base.sched may not be set for each instance and should not
be used for cases such as non-IB tests.

Fixes: 2320c9e ("drm/sched: memset() 'job' in drm_sched_job_init()")
Signed-off-by: David (Ming Qiang) Wu <David.Wu3@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/uvd_v7_0.c

@@ -1288,7 +1288,7 @@ static int uvd_v7_0_ring_patch_cs_in_place(struct amdgpu_cs_parser *p,
 					   struct amdgpu_job *job,
 					   struct amdgpu_ib *ib)
 {
-	struct amdgpu_ring *ring = to_amdgpu_ring(job->base.sched);
+	struct amdgpu_ring *ring = amdgpu_job_ring(job);
 	unsigned i;
 
 	/* No patching necessary for the first instance */