Merge branch 'default_rps_mask-follow-up'

Paolo Abeni says:

====================
net: default_rps_mask follow-up

The first patch namespacify the setting. In the common case, once
proper isolation is in place in the main namespace, forwarding
to/from each child netns will allways happen on the desidered CPUs.

Any additional RPS stage inside the child namespace will not provide
additional isolation and could hurt performance badly if picking a
CPU on a remote node.

The 2nd patch adds more self-tests coverage.
====================

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