net_sched: avoid resetting active qdisc for multiple times

Except for sch_mq and sch_mqprio, each dev queue points to the
same root qdisc, so when we reset the dev queues with
netdev_for_each_tx_queue() we end up resetting the same instance
of the root qdisc for multiple times.

Avoid this by checking the __QDISC_STATE_DEACTIVATED bit in
each iteration, so for sch_mq/sch_mqprio, we still reset all
of them like before, for the rest, we only reset it once.

Reported-by: Václav Zindulka <vaclav.zindulka@tlapnet.cz>
Tested-by: Václav Zindulka <vaclav.zindulka@tlapnet.cz>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>