tipc: fix RDM/DGRAM connect() regression

Fix regression bug introduced in
commit 365ad353c2 ("tipc: reduce risk of user starvation during link
congestion")

Only signal -EDESTADDRREQ for RDM/DGRAM if we don't have a cached
sockaddr.

Fixes: 365ad353c2 ("tipc: reduce risk of user starvation during link congestion")
Signed-off-by: Erik Hugne <erik.hugne@gmail.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/socket.c

@@ -1333,7 +1333,7 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen)
 
 	if (unlikely(!dest)) {
 		dest = &tsk->peer;
-		if (!syn || dest->family != AF_TIPC)
+		if (!syn && dest->family != AF_TIPC)
 			return -EDESTADDRREQ;
 	}