net_sched: sch_codel: defer skb freeing in codel_change()

codel_change() can use rtnl_qdisc_drop()
to defer expensive skb freeing after locks are released.

codel_reset() already has support for deferred skb freeing
because it uses qdisc_reset_queue()
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sched/sch_codel.c

@@ -174,7 +174,7 @@ static int codel_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);