The init script fails if another process has the word "telegraf" in
it, for example if you aren running "vi /etc/opt/telegraf/telegraf.conf"
or "tail -f /var/log/telegraf/telegraf.log". This is because
the "-f" flag to "pgrep" will show processes with the search
string anywhere in the command-line.
This patch turns it around and gets the "ps" output for the process
in the pidfile, and if that line has "telegraf" in it, it considers
it to be running.