init: Check VPD for block_devmode during startup.

Treat the presence of block_devmode in the VPD the same way as the
eponymous crossystem flag.

BUG=chrome-os-partner:50142
TEST=verified that dev mode is blocked when VPD block_devmode is set

Change-Id: I942a16281a5b2ba4e460fe88972543f0f1cd2e80
Reviewed-on: https://chromium-review.googlesource.com/329092
Commit-Ready: Thiemo Nagel <tnagel@chromium.org>
Tested-by: Thiemo Nagel <tnagel@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
1 file changed