net: sched: constify tcf_proto and tc_action

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/act_ipt.c b/net/sched/act_ipt.c
index 9fc211a..60f8f61 100644
--- a/net/sched/act_ipt.c
+++ b/net/sched/act_ipt.c
@@ -195,7 +195,7 @@
 	return tcf_ipt_release(ipt, bind);
 }
 
-static int tcf_ipt(struct sk_buff *skb, struct tc_action *a,
+static int tcf_ipt(struct sk_buff *skb, const struct tc_action *a,
 		   struct tcf_result *res)
 {
 	int ret = 0, result = 0;