Merge branch 'net_sched_actions'

Merge branch 'net_sched_actions'

Jamal Hadi Salim says:

====================
net_sched: actions - Add default lookup and walker

This set of patches provide defaults for lookup and walkers for actions.
Users can override when needed.
It also enforces mandatory action methods to be passed.

Thanks to David Miller who paid attention and made this patch set
much better.
====================

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