buffet: Comments and formating

Renamed local variable.
Added local comment.
Reordered some constants.

BUG=None
TEST=FEATURES=test emerge-gizmo buffet

Change-Id: Ie20e54f4df882f06b8e3912616affe7b50ed7b6d
Reviewed-on: https://chromium-review.googlesource.com/268782
Tested-by: Vitaly Buka <vitalybuka@chromium.org>
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Vitaly Buka <vitalybuka@chromium.org>