net-sched: sch_htb: remove write-only qdisc filter_cnt

The filter_cnt is supposed to count filter references to a class.
Since the qdisc can't be the target of a filter, it doesn't need
a filter_cnt. In fact the counter is never decreased since cls_api
considers a return value of zero a failure and doesn't unbind again.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sched/sch_htb.c

@@ -159,7 +159,6 @@ struct htb_sched {
 
 	/* filters for qdisc itself */
 	struct tcf_proto *filter_list;
-	int filter_cnt;
 
 	int rate2quantum;	/* quant = rate / rate2quantum */
 	psched_time_t now;	/* cached dequeue time */
@@ -1484,7 +1483,6 @@ static struct tcf_proto **htb_find_tcf(struct Qdisc *sch, unsigned long arg)
 static unsigned long htb_bind_filter(struct Qdisc *sch, unsigned long parent,
 				     u32 classid)
 {
-	struct htb_sched *q = qdisc_priv(sch);
 	struct htb_class *cl = htb_find(classid, sch);
 
 	/*if (cl && !cl->level) return 0;
@@ -1498,20 +1496,15 @@ static unsigned long htb_bind_filter(struct Qdisc *sch, unsigned long parent,
 	 */
 	if (cl)
 		cl->filter_cnt++;
-	else
-		q->filter_cnt++;
 	return (unsigned long)cl;
 }
 
 static void htb_unbind_filter(struct Qdisc *sch, unsigned long arg)
 {
-	struct htb_sched *q = qdisc_priv(sch);
 	struct htb_class *cl = (struct htb_class *)arg;
 
 	if (cl)
 		cl->filter_cnt--;
-	else
-		q->filter_cnt--;
 }
 
 static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg)