net_sched: make qdisc_reset() smaller

For some unknown reason qdisc_reset() is using
a convoluted way of freeing two lists of skbs.

Use __skb_queue_purge() instead.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20220414011004.2378350-1-eric.dumazet@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>