Merge branch 'net-sched-fixes-for-sch_qfq'

Pedro Tammela says:

====================
net/sched: fixes for sch_qfq

Patch 1 fixes a regression introduced in 6.4 where the MTU size could be
bigger than 'lmax'.

Patch 3 fixes an issue where the code doesn't account for qdisc_pkt_len()
returning a size bigger then 'lmax'.

Patches 2 and 4 are selftests for the issues above.
====================

Link: https://lore.kernel.org/r/20230711210103.597831-1-pctammela@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>