net: Convert ila_net_ops

net: Convert ila_net_ops

These pernet_operations register and unregister nf hooks.
Also they populate and depopulate ila_net_id-pointed hash
table. The table is changed by hooks during skb processing
and via netlink request. It looks impossible for another
net pernet_operations to force the table reading or writing,
so, they are able to be marked as async.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>