drm/scheduler: always put last_sched fence in entity_fini

Fix the potential memleak since scheduler main thread always
hold one last_sched fence.

Signed-off-by: Pixel Ding <Pixel.Ding@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/scheduler/gpu_scheduler.c

@@ -276,10 +276,10 @@ void drm_sched_entity_cleanup(struct drm_gpu_scheduler *sched,
 			else if (r)
 				DRM_ERROR("fence add callback failed (%d)\n", r);
 		}
-
-		dma_fence_put(entity->last_scheduled);
-		entity->last_scheduled = NULL;
 	}
+
+	dma_fence_put(entity->last_scheduled);
+	entity->last_scheduled = NULL;
 }
 EXPORT_SYMBOL(drm_sched_entity_cleanup);