Merge branch 'WireGuard-CI-and-housekeeping'

Jason A. Donenfeld says:

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WireGuard CI and housekeeping

This is a collection of commits gathered during the last 1.5 weeks since
merging WireGuard. If you'd prefer, I can send tree pull requests
instead, but I figure it might be best for now to just send things as
full patch sets to netdev.

The first part of this adds in the CI test harness that we've been using
for quite some time with success. You can type `make` and get the
selftests running in a fresh VM immediately. This has been an
instrumental tool in developing WireGuard, and I think it'd benefit most
from being in-tree alongside the selftests that are already there. Once
this lands, I plan to get build.wireguard.com building wireguard-
linux.git and net-next.git on every single commit pushed, and do so on a
bunch of different architectures. As this migrates into Linus' tree
eventually and then into net.git, I'll get net.git building there too on
every commit. Future work with this involves generalizing it to include
more networking subsystem tests beyond just WireGuard, but one step at a
time. In the process of porting this to the tree, the builder uncovered
a mistake in the config menu file, which the second commit fixes.

The last three commits are small housekeeping things, fixing spelling
mistakes, replacing call_rcu with kfree_rcu, and removing an unused
include.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>