fsconfig: fix style formating with yapf

A few changes got introduced that yapf re-styles. To make it easy,
keep this file formated to:

yapf -i --style=google fs_config_generator.py

Test: run unit tests

Change-Id: I3160b92d7fd07a4d315dde59f1d20fe4c7587da1
Signed-off-by: William Roberts <william.c.roberts@intel.com>