BUTTERFLY_FACTORY: Fix keyboard test cannot work.

For keyboard test, it invokes evtest with /dev/input/event%d to
capture keyboard event.

However, the event id is hard coded and may vary in different machines
or during different boot. If it is not default value (6), we cannot
capture keyboard event to start test.

Fix it by using '/dev/input/by-path/platform-i8042-serio-0-event-kbd'
for evtest.

BUG=chrome-os-partner:19379
TEST=Manually run factory keyboard test on my DUT.

Change-Id: Id12da1459e6995441ac57bc3b27040bbfa9665b7
Reviewed-on: https://gerrit.chromium.org/gerrit/51269
Tested-by: Bowgo Tsai <bowgotsai@chromium.org>
Commit-Queue: Bowgo Tsai <bowgotsai@chromium.org>
Reviewed-by: Bowgo Tsai <bowgotsai@chromium.org>
1 file changed