add --daemon to command run line - for run propertly in daemon mode
currently suggest use RunAsDaemon:Yes
also I think
# Set the following variables for your setup
# pid file defaults to same dir as config file (edit $MRTGPREFIX/mrtg)
# if you don't like it.
may need configure in conf.d/mrtg ;)
also may add variable what may use in --logging option
New and improved init.d and matching conf.d file have been committed.