libchromeos: Fix linting issues

This fixes the easiest linting issues introduced by the move from platform to
platform2 (mostly complete import path and correct header guard).

A second CL will address non trivial issues.

BUG=chromium:391075
TEST=FEATURES=test emerge-amd64-generic libchromeos bootstat platform2
TEST=emerge-daisy libchromeos bootstat platform2

Change-Id: Ide30a251b72c605a7a50f327bd89915bb3235498
Reviewed-on: https://chromium-review.googlesource.com/206519
Reviewed-by: Alex Vakulenko <[email protected]>
Tested-by: Bertrand Simonnet <[email protected]>
Commit-Queue: Ben Chan <[email protected]>
36 files changed