[AF_UNIX]: Test against sk_max_ack_backlog properly.

This brings things inline with the sk_acceptq_is_full() bug
fix.  The limit test should be x >= sk_max_ack_backlog.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/unix/af_unix.c

@@ -934,7 +934,7 @@ static long unix_wait_for_peer(struct sock *other, long timeo)
 
 	sched = !sock_flag(other, SOCK_DEAD) &&
 		!(other->sk_shutdown & RCV_SHUTDOWN) &&
-		(skb_queue_len(&other->sk_receive_queue) >
+		(skb_queue_len(&other->sk_receive_queue) >=
 		 other->sk_max_ack_backlog);
 
 	unix_state_runlock(other);
@@ -1008,7 +1008,7 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 	if (other->sk_state != TCP_LISTEN)
 		goto out_unlock;
 
-	if (skb_queue_len(&other->sk_receive_queue) >
+	if (skb_queue_len(&other->sk_receive_queue) >=
 	    other->sk_max_ack_backlog) {
 		err = -EAGAIN;
 		if (!timeo)
@@ -1381,7 +1381,7 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
 	}
 
 	if (unix_peer(other) != sk &&
-	    (skb_queue_len(&other->sk_receive_queue) >
+	    (skb_queue_len(&other->sk_receive_queue) >=
 	     other->sk_max_ack_backlog)) {
 		if (!timeo) {
 			err = -EAGAIN;