vboot: Split partition and vblock verification from LoadKernel()

LoadKernel() was a big function which did everything from looping over
partitions on a drive to loading the data within them to calling the
low-level verification functions on that data.  Split it apart into more
manageable chunks.  This also reduces indentation of the inner parts of
the code, whic increases readability.

No outwardly-visible functionality changes.

TEST=make runtests; emerge-kevin coreboot depthcharge

Change-Id: Iea79e70163f5d9f1a9d0d897e4a9bacc925a742d
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/404919
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>
7 files changed