Pre 5.1-rc1 build issue

[Bruno Wolff III]

On Wed, Mar 13, 2019 at 13:38:18 -0500,
  Bruno Wolff III <bruno at wolff.to> wrote:
>Commit https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d2c5c103b1337f590b7edf1509a6e294bdf22402
>removed net/netfilter/nf_nat_core.h, which breaks wireguard builds for 
>5.1.0-0.rc0.git5.2.fc31.x86_64.
>
>It sounds like it isn't needed any more from the commit message.

There are also some rcu changes that I just guessed on fixes for. I think 
this change was covered in Paul McKenney's LCA talk in January.

I got something that seems to be working. So I'm good until the real fixes 
are ready.