net/sched/sch_hfsc.c: add unlikely() in qdisc_peek_len()

The condition can only succeed on wrong configurations.
Signed-off-by: Michal Soltys <soltys@ziu.info>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_hfsc.c

@@ -882,7 +882,7 @@ qdisc_peek_len(struct Qdisc *sch)
 	unsigned int len;
 
 	skb = sch->ops->peek(sch);
-	if (skb == NULL) {
+	if (unlikely(skb == NULL)) {
 		qdisc_warn_nonwc("qdisc_peek_len", sch);
 		return 0;
 	}