Code review comment for ~guoqiao/charm-hw-health:LP1906991-chown-output-files

NOTE:

This patch is only trying to fix current bug with minimal changes.

There is suggestion to create a subdir for each tool, so we can manage files and permissions in an easier way. e.g.:

/var/lib/nagios/ipmi/ipmi_sensors.out
/var/lib/nagios/ipmi/ipmi_exclude

I will submit another patch for that, after this one if merged.