Merge branch 'convert-pernet_operations-part4'

Kirill Tkhai says:

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Converting pernet_operations (part #4)

this series continues to review and to convert pernet_operations
to make them possible to be executed in parallel for several
net namespaces in the same time. The patches touch mostly netfilter,
also there are small number of changes in other places.
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Signed-off-by: David S. Miller <davem@davemloft.net>