[X25]: Fix for broken x25 module.

When a user-space server application calls bind on a socket, then in kernel
space this bound socket is considered 'x25-linked' and the SOCK_ZAPPED flag
is unset.(As in x25_bind()/af_x25.c).

Now when a user-space client application attempts to connect to the server
on the listening socket, if the kernel accepts this in-coming call, then it
returns a new socket to userland and attempts to reply to the caller.

The reply/x25_sendmsg() will fail, because the new socket created on
call-accept has its SOCK_ZAPPED flag set by x25_make_new().
(sock_init_data() called by x25_alloc_socket() called by x25_make_new()
sets the flag to SOCK_ZAPPED)).

Fix: Using the sock_copy_flag() routine available in sock.h fixes this.

Tested on 32 and 64 bit kernels with x25 over tcp.

Signed-off-by: Shaun Pereira <pereira.shaun@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/x25/af_x25.c

@@ -540,12 +540,7 @@ static struct sock *x25_make_new(struct sock *osk)
 	sk->sk_state       = TCP_ESTABLISHED;
 	sk->sk_sleep       = osk->sk_sleep;
 	sk->sk_backlog_rcv = osk->sk_backlog_rcv;
-
-	if (sock_flag(osk, SOCK_ZAPPED))
-		sock_set_flag(sk, SOCK_ZAPPED);
-
-	if (sock_flag(osk, SOCK_DBG))
-		sock_set_flag(sk, SOCK_DBG);
+	sock_copy_flags(sk, osk);
 
 	ox25 = x25_sk(osk);
 	x25->t21        = ox25->t21;