Fix '/etc/init.d/supervisord status'

"service supervisord status" reports wrong status (servise is up)
even when supervisor is down. It uses "supervisorctl status" which
returns exit code "0" when supervisor is down. We're adding
additional check for status() function to fix this.

Closes-bug: #1356805

Change-Id: I6979d9b54c1e9fed2f1629ebc1edc741f2136b56
Merge "Fix '/etc/init.d/supervisord status'"