vboot/vboot_kernel: check developer key hash in separate function

Create vb2_verify_kernel_dev_key_hash to encapsulate
developer key hash checking logic.

Also correct formatting of developer key hash when printed
to console.

This CL is part of a series to merge vboot1 and vboot2.0
kernel verification code; see b/181739551.

TEST=make clean && make runtests

Signed-off-by: Joel Kitching <kitching@google.com>
Change-Id: I0253e1e960fb966b67b4643794585ed8355d8efb
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2825268
Tested-by: Joel Kitching <kitching@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Commit-Queue: Joel Kitching <kitching@chromium.org>
2 files changed