rtnetlink: Remove passing of attributes into rtnl_doit functions

With decnet converted, we can finally get rid of rta_buf and its
computations around it. It also gets rid of the minimal header
length verification since all message handlers do that explicitly
anyway.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 964f5e4..9a04b98 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -118,7 +118,7 @@
 
 /* Add/change/delete/get a filter node */
 
-static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
+static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n)
 {
 	struct net *net = sock_net(skb->sk);
 	struct nlattr *tca[TCA_MAX + 1];