Remove disk firmware upgrade check file

During postinstll, remove the check file to force a disk
firmware check at first reboot.
This change allows removing a cksum call at boot in disk firmware conf
file.

TEST=Install image with cros flash, check the file is removed and
recreated at boot.
TEST=Install image with USB key. Check sda1 partition does not
contain the check file anymore.

BUG=chromium:340883

Change-Id: I556291f8b74c50cef395ce3026e1aa7f2f8f6b6b
Reviewed-on: https://chromium-review.googlesource.com/186172
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Commit-Queue: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
1 file changed