futility: updater: improve updater console output

To help debugging:

- Print equivalent flashrom commands when reading and writing.
- Print <sys-flash> instead of <none> in 'Current system:' message.
- Always print the detected model from libcrosid.
- After writing to flash, print a new line.

BUG=None
TEST=make; build and run test
BRANCH=None

Change-Id: I34a73ec1c968a98a9fca649c65863aa43ca39ca8
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3461090
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
Commit-Queue: Yu-Ping Wu <yupingso@chromium.org>
3 files changed