pkt_sched: Update qdisc requeue stats in dev_requeue_skb()

After the last change of requeuing there is no info about such
incidents in tc stats. This patch updates the counter, but we should
consider this should differ from previous stats because of additional
checks preventing to repeat this. On the other hand, previous stats
didn't include requeuing of gso_segmented skbs.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_generic.c

@@ -45,6 +45,7 @@ static inline int qdisc_qlen(struct Qdisc *q)
 static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
 {
 	q->gso_skb = skb;
+	q->qstats.requeues++;
 	__netif_schedule(q);
 
 	return 0;