Merge branch 'qdisc-null-deref'

Merge branch 'qdisc-null-deref'

Zhengchao Shao says:

====================
net: fix null pointer access issue in qdisc

These three patches fix the same type of problem. Set the default qdisc,
and then construct an init failure scenario when the dev qdisc is
configured on mqprio to trigger the reset process. NULL pointer access
may occur during the reset process.

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v2: for fq_codel, revert the patch
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====================

Signed-off-by: David S. Miller <davem@davemloft.net>