pkt_sched: sch_generic: Kfree gso_skb in qdisc_reset()

Since gso_skb is re-used for qdisc_peek_dequeued(), and this skb is
counted in the qdisc->q.qlen, it has to be kfreed during qdisc_reset()
when qlen is zeroed.

With help from David S. Miller <davem@davemloft.net>

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

net/sched/sch_generic.c

@@ -542,6 +542,9 @@ void qdisc_reset(struct Qdisc *qdisc)
 
 	if (ops->reset)
 		ops->reset(qdisc);
+
+	kfree_skb(qdisc->gso_skb);
+	qdisc->gso_skb = NULL;
 }
 EXPORT_SYMBOL(qdisc_reset);