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: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>