lint: handle indentation of section subtext

Check the indentation of the sections themselves.

BUG=chromium:485005
TEST=`cros lint` on all files pass, and catches some bad cases

Change-Id: If5fceb5e561741dc60aecbe0615a02dd5df948a1
Reviewed-on: https://chromium-review.googlesource.com/269646
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
2 files changed