fmap.py: fix docstring style issues

`cros lint` flags a bunch of issues with these docstrings.
Clean up the style to pass all the checks.

BUG=chromium:982465
TEST=`cros lint` on these no longer complains about docstrings

Change-Id: I7caf0275ce1441bb4031f7d8e9e0ac96bfdf9b05
Reviewed-on: https://chromium-review.googlesource.com/1693885
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Duncan Laurie <dlaurie@google.com>
1 file changed