Input: add compat support for sysfs and /proc capabilities output

Input core displays capabilities bitmasks in form of one or more longs printed
in hex form and separated by spaces. Unfortunately it does not work well
for 32-bit applications running on 64-bit kernels since applications expect
that number is "worth" only 32 bits when kernel advances by 64 bits.

Fix that by ensuring that output produced for compat tasks uses 32-bit units.

Reported-and-tested-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>