Merge branch 'pernet-convert-part7.1'

Kirill Tkhai says:

====================
Converting pernet_operations (part #7.1)

this is a resending of the 4 patches from path #7.

Anna kindly reviewed them and suggested to take the patches
through net tree, since there is pernet_operations::async only
in net-next.git.

There is Anna's acks on every header, the rest of patch
has no changes.
====================

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