net_sched: make tcf_hash_check() boolean

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/act_vlan.c b/net/sched/act_vlan.c
index b075d50..db9b7ed 100644
--- a/net/sched/act_vlan.c
+++ b/net/sched/act_vlan.c
@@ -77,8 +77,8 @@
 	int action;
 	__be16 push_vid = 0;
 	__be16 push_proto = 0;
-	int ret = 0, exists = 0;
-	int err;
+	bool exists = false;
+	int ret = 0, err;
 
 	if (!nla)
 		return -EINVAL;