rbd: remove parent devices on probe error

When an error occurs while finishing probing a device it is assumed
that parent devices get cleaned up when deleting a device.  They
don't.  Add a call to clean them up.  Note that this means the
parent spec will already be cleaned up so it doesn't have to be
in one of the rbd_add() error paths.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

drivers/block/rbd.c

@@ -4813,8 +4813,7 @@ static int rbd_dev_probe_finish(struct rbd_device *rbd_dev)
 	return ret;
 
 err_out_bus:
-	/* this will also clean up rest of rbd_dev stuff */
-
+	rbd_dev_remove_parent(rbd_dev);
 	rbd_bus_del_dev(rbd_dev);
 
 	return ret;
@@ -4931,7 +4930,6 @@ static ssize_t rbd_add(struct bus_type *bus,
 
 	return count;
 err_out_rbd_dev:
-	rbd_spec_put(rbd_dev->parent_spec);
 	kfree(rbd_dev->header_name);
 	rbd_dev_destroy(rbd_dev);
 err_out_client: