drm/amd/scheduler: add WARN_ON for s_fence->parent

Signed-off-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/scheduler/gpu_scheduler.c

@@ -241,6 +241,7 @@ void amd_sched_entity_fini(struct amd_gpu_scheduler *sched,
 			amd_sched_fence_scheduled(s_fence);
 			dma_fence_set_error(&s_fence->finished, -ESRCH);
 			amd_sched_fence_finished(s_fence);
+			WARN_ON(s_fence->parent);
 			dma_fence_put(&s_fence->finished);
 			sched->ops->free_job(job);
 		}