[AF_UNIX]: Don't lose ECONNRESET in unix_seqpacket_sendmsg()

The fix for SELinux w/SOCK_SEQPACKET had an error,
noted by Alan Cox.  This fixes it.
Signed-off-by: James Morris <jmorris@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/unix/af_unix.c

@@ -1513,13 +1513,18 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
 static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock,
 				  struct msghdr *msg, size_t len)
 {
+	int err;
 	struct sock *sk = sock->sk;
 	
+	err = sock_error(sk);
+	if (err)
+		return err;
+
 	if (sk->sk_state != TCP_ESTABLISHED)
 		return -ENOTCONN;
 
-	if (msg->msg_name || msg->msg_namelen)
-		return -EINVAL;
+	if (msg->msg_namelen)
+		msg->msg_namelen = 0;
 
 	return unix_dgram_sendmsg(kiocb, sock, msg, len);
 }