Linux 4.2 rc4

Another week, another rc.

I really wish that things were calming down, but it hasn't happened
quite yet. It's not like this is particularly big or scary, but it's
also not at the stage where it's really starting to get quiet and the
bugs are really small and esoteric.

So we still had some bugs due to the low-level x86 asm cleanup work,
and the 32-bit compat 'syscall' instruction (only used on AMD) was
subtly broken. That should be all fixed now, so if you run a 64-bit
kernel and have 32-bit user space (including things like wine etc) and
saw problems earlier, go ahead and update.

Of course, please go ahead and update even if you didn't see problems,
just to test the new rc.

Other than that issue, it's mostly drivers and networking. USB, gpu,
mmc, network drivers, sound. With some ARM noise (but even that is
mostly driver-related: dts updates due to MMC fixes). And a few small
filesystem fixes.

Go forth and test,