X.25 remove bkl in listen

Listen updates socket values and needs lock_sock.
Signed-off-by: Andrew Hendry <andrew.hendry@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/x25/af_x25.c

@@ -507,14 +507,14 @@ static int x25_listen(struct socket *sock, int backlog)
 	struct sock *sk = sock->sk;
 	int rc = -EOPNOTSUPP;
 
-	lock_kernel();
+	lock_sock(sk);
 	if (sk->sk_state != TCP_LISTEN) {
 		memset(&x25_sk(sk)->dest_addr, 0, X25_ADDR_LEN);
 		sk->sk_max_ack_backlog = backlog;
 		sk->sk_state           = TCP_LISTEN;
 		rc = 0;
 	}
-	unlock_kernel();
+	release_sock(sk);
 
 	return rc;
 }