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/include/net/sch_generic.h b/include/net/sch_generic.h
index d9611e0..4616f46 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -188,7 +188,8 @@
 
 	unsigned long		(*get)(struct tcf_proto*, u32 handle);
 	void			(*put)(struct tcf_proto*, unsigned long);
-	int			(*change)(struct tcf_proto*, unsigned long,
+	int			(*change)(struct sk_buff *,
+					struct tcf_proto*, unsigned long,
 					u32 handle, struct nlattr **,
 					unsigned long *);
 	int			(*delete)(struct tcf_proto*, unsigned long);