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_simple.c b/net/sched/act_simple.c
index a34a22d..73e0a3a 100644
--- a/net/sched/act_simple.c
+++ b/net/sched/act_simple.c
@@ -36,7 +36,8 @@
 };
 
 #define SIMP_MAX_DATA	32
-static int tcf_simp(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
+static int tcf_simp(struct sk_buff *skb, const struct tc_action *a,
+		    struct tcf_result *res)
 {
 	struct tcf_defact *d = a->priv;