drm/amdgpu: remove unused member

This lock isn't used any more.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h

@@ -187,9 +187,6 @@ struct amdgpu_vm {
 	struct amdgpu_vm_pt     root;
 	struct dma_fence	*last_update;
 
-	/* protecting freed */
-	spinlock_t		freed_lock;
-
 	/* Scheduler entity for page table updates */
 	struct drm_sched_entity	entity;