drm/radeon: double lock typo in radeon_vm_bo_rmv()

The second lock should be an unlock or it causes a deadlock.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_gart.c

@@ -603,7 +603,7 @@ int radeon_vm_bo_rmv(struct radeon_device *rdev,
 	radeon_vm_bo_update_pte(rdev, vm, bo, NULL);
 	radeon_mutex_unlock(&rdev->cs_mutex);
 	list_del(&bo_va->vm_list);
-	mutex_lock(&vm->mutex);
+	mutex_unlock(&vm->mutex);
 
 	kfree(bo_va);
 	return 0;