Linux 4.19 rc3

Another week, another rc.

Things look fairly normal. The diffstat shows some unusual patterns,
but that's partly due to some late nds32 updates and nilfs2 got the
copyright messages converted to SPDX, and that just shows up like a
sore thumb in the diffstat.

But other than odd details like that, nothing really stands out.
Drivers, networking and arch fixes, with misc random small changes all
over (eg btrfs fixes).

Shortlog appended, in case people want to look at the details.