factory_install: Clear block_devmode settings for RMA.

When resetting device, clear block_devmode settings from VPD and
crossystem.

This is required for RMA process. Only devices with write protection
disabled can reach factory_installer using RMA shim so this is fine for
security concern.

BUG=chrome-os-partner:61540
TEST=None

Change-Id: I51cc322ccc77658209d8fc9cca07a8d5ff7227fc
Reviewed-on: https://chromium-review.googlesource.com/431600
Commit-Ready: Hung-Te Lin <hungte@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Thiemo Nagel <tnagel@chromium.org>
1 file changed