From: Florian Westphal <fw@strlen.de>
Date: Fri, 11 Dec 2015 12:19:04 +0100

So if we do ILA in init ns it & pass such skbs to other netns
it would be preferable to use nf_register_net_hooks in a namespace
once the first ila translation is added within that namespace.

Right, the idea is that we want to do the ILA address translation
before most other things in the stack see the headers.

In particular, we want this to happen before early socket demux.