Fix regex, improve error messages Running autotest to validate firmware upgrade uncovered a cut&paste error in the the firmware regex. The error prevents firmware upgrade. Also when the package is missing a rule file, no error was reported. BUG=chromium:328624 TEST=unit test TEST=apply firmware packages to upgrade/downgrade and invalid package Change-Id: I1365a539d0572fbdafd788609a26f41b7ca34832 Reviewed-on: https://chromium-review.googlesource.com/186753 Reviewed-by: Mike Frysinger <[email protected]> Commit-Queue: Gwendal Grignou <[email protected]> Tested-by: Gwendal Grignou <[email protected]>