cros_bundle_firmware: Zero out vblock areas

BUG=chromium:595715
BRANCH=none
TEST=verify bit-equivalence of regions between image.bin and cb_with_fmap
with CL:397219 or similar.

Change-Id: I0e6e029a7bb645f92b06a8263d5b2d67a65bf16d
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://chromium-review.googlesource.com/397623
Commit-Ready: Patrick Georgi <pgeorgi@chromium.org>
Tested-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-by: Patrick Georgi <pgeorgi@chromium.org>
1 file changed