commit affa80bd upstream.

When running a 32-bit userspace on a 64-bit kernel, the UI_SET_PHYS
ioctl needs to be treated with special care, as it has the pointer
size encoded in the command.
Signed-off-by: Ricky Liang <jcliang@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>