nbd: share nbd_put and return by goto put_nbd

Replace the following two statements by the statement “goto put_nbd;”

	nbd_put(nbd);
	return 0;

Signed-off-by: Sun Ke <[email protected]>
Suggested-by: Markus Elfring <[email protected]>
Reviewed-by: Josef Bacik <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

Author: sunke-lp

drivers/block/nbd.c

@@ -2015,12 +2015,11 @@ static int nbd_genl_disconnect(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 	}
 	mutex_unlock(&nbd_index_mutex);
-	if (!refcount_inc_not_zero(&nbd->config_refs)) {
-		nbd_put(nbd);
-		return 0;
-	}
+	if (!refcount_inc_not_zero(&nbd->config_refs))
+		goto put_nbd;
 	nbd_disconnect_and_put(nbd);
 	nbd_config_put(nbd);
+put_nbd:
 	nbd_put(nbd);
 	return 0;
 }