netfilter: nf_conntrack: Add a struct net parameter to l4_pkt_to_tuple

As gre does not have the srckey in the packet gre_pkt_to_tuple
needs to perform a lookup in it's per network namespace tables.

Pass in the proper network namespace to all pkt_to_tuple
implementations to ensure gre (and any similar protocols) can get this
right.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/sched/act_connmark.c b/net/sched/act_connmark.c
index 413ac39..bb41699 100644
--- a/net/sched/act_connmark.c
+++ b/net/sched/act_connmark.c
@@ -68,7 +68,7 @@
 	}
 
 	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
-			       proto, &tuple))
+			       proto, ca->net, &tuple))
 		goto out;
 
 	zone.id = ca->zone;