Fix the init script so mcollective can be restarted properly

Fix the init script so mcollective can be restarted properly

The check for a running mcollective process is totally wrong and fails
to handle a stale pid file:

if [ -f $(cat /proc/$(cat $pidfile)/exe > /dev/null) ] ; then

Basically it's

if [ -f ]; then echo "Someone can't write shell scripts"; fi

This error breaks image based deployment. During the first boot after
the image based provisioning cloud init reconfigures mcollective to use
rabbitmq for communication and restarts it. However the restart gets
suppressed due to a bug in the sysv-style init script, so OpenStack
deployment does not start (and eventually times out).

The error is non-deterministic since sometimes cloud-init manages to
configure mcollective before it actually gets started (thus the correct
configuration is used despite the skipped restart).

Related-Bug: #1407634
Change-Id: I1608492ff807a1662fa1453c6e50d9fb4eb234bd