ax25: Quick fix for making sure unaccepted sockets get destroyed.

Since we reverted 30902dc3cb0ea1cfc7ac2b17bcf478ff98420d74 ("ax25: Fix
std timer socket destroy handling.") we have to put some kind of fix
in to cure the issue whereby unaccepted connections do not get destroyed.

The approach used here is from Tihomir Heidelberg - 9a4gl

Signed-off-by: David S. Miller <davem@davemloft.net>

net/ax25/af_ax25.c

@@ -317,6 +317,9 @@ void ax25_destroy_socket(ax25_cb *ax25)
 				/* Queue the unaccepted socket for death */
 				sock_orphan(skb->sk);
 
+				/* 9A4GL: hack to release unaccepted sockets */
+				skb->sk->sk_state = TCP_LISTEN;
+
 				ax25_start_heartbeat(sax25);
 				sax25->state = AX25_STATE_0;
 			}