[ROSE]: rose_heartbeat_expiry() locking fix

Missing unlock, as noted by Ted Unangst <tedu@coverity.com>.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

net/rose/rose_timer.c

@@ -138,6 +138,7 @@ static void rose_heartbeat_expiry(unsigned long param)
 		   is accepted() it isn't 'dead' so doesn't get removed. */
 		if (sock_flag(sk, SOCK_DESTROY) ||
 		    (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) {
+			bh_unlock_sock(sk);
 			rose_destroy_socket(sk);
 			return;
 		}