tipc: fix node reference count bug

Commit 5405ff6e ("tipc: convert node lock to rwlock")
introduced a bug to the node reference counter handling. When a
message is successfully sent in the function tipc_node_xmit(),
we return directly after releasing the node lock, instead of
continuing and decrementing the node reference counter as we
should do.

This commit fixes this bug.
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/node.c

@@ -1189,20 +1189,19 @@ int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
 			spin_unlock_bh(&le->lock);
 		}
 		tipc_node_read_unlock(n);
-		if (likely(!skb_queue_empty(&xmitq))) {
+		if (likely(!rc))
 			tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
-			return 0;
-		}
-		if (unlikely(rc == -ENOBUFS))
+		else if (rc == -ENOBUFS)
 			tipc_node_link_down(n, bearer_id, false);
 		tipc_node_put(n);
 		return rc;
 	}
 
-	if (unlikely(!in_own_node(net, dnode)))
-		return rc;
+	if (likely(in_own_node(net, dnode))) {
 		tipc_sk_rcv(net, list);
 		return 0;
+	}
+	return rc;
 }
 
 /* tipc_node_xmit_skb(): send single buffer to destination