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 <vapier@chromium.org>
Commit-Queue: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
5 files changed
tree: 0ed07da05f5d390508d6a8a2c0af58eaedd3eb26
  1. LICENSE
  2. OWNERS
  3. README
  4. README.chromium
  5. scripts/
  6. tests/