When parsing a frame template with a placeholder indicating the number
of buttons present on the frame its value was incorrectly set on big
endian architectures due to double little endian conversion.

In order to reproduce the issue and verify the fix, run the HID KUnit
tests on the PowerPC architecture:

  $ ./tools/testing/kunit/kunit.py run --kunitconfig=drivers/hid \
    --arch=powerpc --cross_compile=powerpc64-linux-gnu-

Fixes: 867c8925 ("HID: uclogic: Allow to generate frame templates")
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>