net_sched: sch_pie: defer skb freeing

pie_change() can use rtnl_qdisc_drop() to benefit from
deferred freeing.

pie_reset() is already using qdisc_reset_queue()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_pie.c

@@ -234,7 +234,7 @@ static int pie_change(struct Qdisc *sch, struct nlattr *opt)
 
 		dropped += qdisc_pkt_len(skb);
 		qdisc_qstats_backlog_dec(sch, skb);
-		qdisc_drop(skb, sch);
+		rtnl_qdisc_drop(skb, sch);
 	}
 	qdisc_tree_reduce_backlog(sch, qlen - sch->q.qlen, dropped);