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_police.c b/net/sched/act_police.c
index b3b9b32..6fb3f5a 100644
--- a/net/sched/act_police.c
+++ b/net/sched/act_police.c
@@ -282,7 +282,7 @@
 	return ret;
 }
 
-static int tcf_act_police(struct sk_buff *skb, struct tc_action *a,
+static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a,
 			  struct tcf_result *res)
 {
 	struct tcf_police *police = a->priv;