net sched: Pass the skb into change so it can access NETLINK_CB

cls_flow.c plays with uids and gids.  Unless I misread that
code it is possible for classifiers to depend on the specific uid and
gid values.  Therefore I need to know the user namespace of the
netlink socket that is installing the packet classifiers.  Pass
in the rtnetlink skb so I can access the NETLINK_CB of the passed
packet.  In particular I want access to sk_user_ns(NETLINK_CB(in_skb).ssk).

Pass in not the user namespace but the incomming rtnetlink skb into
the the classifier change routines as that is generally the more useful
parameter.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 6dd1131..dc3ef5a 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -319,7 +319,7 @@
 		}
 	}
 
-	err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh);
+	err = tp->ops->change(skb, tp, cl, t->tcm_handle, tca, &fh);
 	if (err == 0) {
 		if (tp_created) {
 			spin_lock_bh(root_lock);