Revert "ax25: Fix std timer socket destroy handling."

This reverts commit 30902dc3.

It causes all kinds of problems, based upon a report by
Bernard (f6bvp) and analysis by Jarek Poplawski.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ax25/ax25_std_timer.c

@@ -39,9 +39,11 @@ void ax25_std_heartbeat_expiry(ax25_cb *ax25)
 
 	switch (ax25->state) {
 	case AX25_STATE_0:
-		if (!sk ||
-		    sock_flag(sk, SOCK_DESTROY) ||
-		    sock_flag(sk, SOCK_DEAD)) {
+		/* Magic here: If we listen() and a new link dies before it
+		   is accepted() it isn't 'dead' so doesn't get removed. */
+		if (!sk || sock_flag(sk, SOCK_DESTROY) ||
+		    (sk->sk_state == TCP_LISTEN &&
+		     sock_flag(sk, SOCK_DEAD))) {
 			if (sk) {
 				sock_hold(sk);
 				ax25_destroy_socket(ax25);