net: sched: cls_api: introduce tc_cls_bind_class() helper

All the bind_class callback duplicate the same logic, this patch
introduces tc_cls_bind_class() helper for common usage.
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/pkt_cls.h

@@ -210,6 +210,18 @@ tcf_unbind_filter(struct tcf_proto *tp, struct tcf_result *r)
 	__tcf_unbind_filter(q, r);
 }
 
+static inline void tc_cls_bind_class(u32 classid, unsigned long cl,
+				     void *q, struct tcf_result *res,
+				     unsigned long base)
+{
+	if (res->classid == classid) {
+		if (cl)
+			__tcf_bind_filter(q, res, base);
+		else
+			__tcf_unbind_filter(q, res);
+	}
+}
+
 struct tcf_exts {
 #ifdef CONFIG_NET_CLS_ACT
 	__u32	type; /* for backward compat(TCA_OLD_COMPAT) */