making wireguard work on RHEL7/etc.

[Jason A. Donenfeld]

On Mon, Jun 26, 2017 at 08:55:02PM +0100, wireguard at wut.to wrote:
> I think this might work ...
> 
> I was still able to compile on Amazon AMI/4.9.32 Kernel

Thanks! This isn't the proper way to submit a patch, but I'll examine
the diff and roll something satisfactory myself. Thanks a bunch for
doing all the hard work with this. Hopefully the next wireguard snapshot
will have out-of-the-box RHEL support.