Merge branch 'net-selftests'

Petr Machata says:

====================
selftests: Use busywait() in a couple places

Two helper function for active waiting for an event were recently
introduced: busywait() as the active-waiting tool, and until_counter_is()
as a configurable predicate that can be plugged into busywait(). Use these
in tc_common and mlxsw's qos_defprio instead of hand-coding equivalents.

Patches #1 and #2 extend lib.sh facilities to make the transition possible.
Patch #3 converts tc_common, and patch #4 qos_defprio.
====================

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