network_diagnostics: clean up some stale flimflam checks

Since we no longer have flimflam on the image, flimflam will
never be running. Remove checks for the flimflam process, since
they generate irrelevant error messages.

BUG=chromium:306914
TEST=Manual (see below)

Manual test
-----------
- # network_diagnostics --flimflam
- check that there is no "FAIL: flimflam is stopped"
- check that there is no "Listing of /var/run/flimflam"

- # stop shill
- # ifconfig eth0 down
- # ifconfig wlan0 down
- # network_diagnostics --interface
- check that "FAIL: shill is stopped" is present
- check that "FAIL: flimflam is stopped" is NOT present

Change-Id: I5a450c9b198251751a93423bc7edd7580e871e01
Reviewed-on: https://chromium-review.googlesource.com/176266
Tested-by: mukesh agrawal <quiche@chromium.org>
Reviewed-by: Paul Stewart <pstew@chromium.org>
Commit-Queue: mukesh agrawal <quiche@chromium.org>
1 file changed