tipc: make tipc_link_send_sections_fast exit earlier

Once message build request function returns invalid code, the
process of sending message cannot continue. So in case of message
build failure, tipc_link_send_sections_fast() should return
immediately.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/link.c

@@ -1082,6 +1082,9 @@ again:
 	 */
 	res = tipc_msg_build(hdr, msg_sect, num_sect, total_len,
 			     sender->max_pkt, &buf);
+	/* Exit if build request was invalid */
+	if (unlikely(res < 0))
+		return res;
 
 	read_lock_bh(&tipc_net_lock);
 	node = tipc_node_find(destaddr);
@@ -1098,10 +1101,6 @@ exit:
 				return res;
 			}
 
-			/* Exit if build request was invalid */
-			if (unlikely(res < 0))
-				goto exit;
-
 			/* Exit if link (or bearer) is congested */
 			if (link_congested(l_ptr) ||
 			    tipc_bearer_blocked(l_ptr->b_ptr)) {