[ICSK]: Generalise tcp_listen_{start,stop}

This also moved inet_iif from tcp to inet_hashtables.h, as it is
needed by the inet_lookup callers, perhaps this needs a bit of
polishing, but for now seems fine.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 2f605b9..b966102 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -431,11 +431,6 @@
 	return err;
 }
 
-static inline int inet_iif(const struct sk_buff *skb)
-{
-	return ((struct rtable *)skb->dst)->rt_iif;
-}
-
 /*
  * This routine does path mtu discovery as defined in RFC1191.
  */
@@ -1993,6 +1988,7 @@
 	.get_port		= tcp_v4_get_port,
 	.enter_memory_pressure	= tcp_enter_memory_pressure,
 	.sockets_allocated	= &tcp_sockets_allocated,
+	.orphan_count		= &tcp_orphan_count,
 	.memory_allocated	= &tcp_memory_allocated,
 	.memory_pressure	= &tcp_memory_pressure,
 	.sysctl_mem		= sysctl_tcp_mem,