Linux 4.18 rc6

So this was the week when the other shoe dropped ...  The reason the
two previous rc releases were so nice and small was that David hadn't
sent me much networking fixes, and they came in this week.

That said, it's not really a huge rc this week either, so it's all
good. But the networking pull this week does mean that almost exactly
half of the diff is core networking, network drivers, or networking
documentation updates.

The rest is other drivers (mostly gpu, but also scsi, nvma, pci,
pinctrl..), some arch updates (arc, x86, nds32, powerpc), and "misc"
(tooling, header files, some vm and fs noise).

The small but nasty VM bug we had earlier did indeed get fixed last
rc, but there was some 32-bit fallout from the fix, so rc5 still had
issues. But I'm hopeful that rc6 _really_ fixed all the cases.

Shortlog appended for people who want to just get an overview of the details,