net_sched: switch to exit_batch for action pernet ops

Since we now hold RTNL lock in tc_action_net_exit(), it is good to
batch them to speedup tc action dismantle.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/act_gact.c b/net/sched/act_gact.c
index e29a48e..9d632e9 100644
--- a/net/sched/act_gact.c
+++ b/net/sched/act_gact.c
@@ -235,16 +235,14 @@
 	return tc_action_net_init(tn, &act_gact_ops);
 }
 
-static void __net_exit gact_exit_net(struct net *net)
+static void __net_exit gact_exit_net(struct list_head *net_list)
 {
-	struct tc_action_net *tn = net_generic(net, gact_net_id);
-
-	tc_action_net_exit(tn);
+	tc_action_net_exit(net_list, gact_net_id);
 }
 
 static struct pernet_operations gact_net_ops = {
 	.init = gact_init_net,
-	.exit = gact_exit_net,
+	.exit_batch = gact_exit_net,
 	.id   = &gact_net_id,
 	.size = sizeof(struct tc_action_net),
 };