vboot/altfw: fix up some altfw code

Rather than the caller picking and choosing between vb2_run_altfw
and vb2_try_alt_fw, always use the "try" function, and manually
specify the `allowed` argument.

Fix up some comment styles.

Reverse the order of vb2_commit_data and secdata_kernel_lock
calls, and check the return value of vb2_commit_data.

BUG=b:124141368
TEST=make clean && make runtests
BRANCH=none

Change-Id: Ib6b2752ba1b9be66401612a46f9c1b9353669c27
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/1776286
Tested-by: Joel Kitching <kitching@chromium.org>
Commit-Queue: Joel Kitching <kitching@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
4 files changed