disk-logger used to save persistent log as file in disk.
log path: /var/log/acrn-dm/
each log file size is 2MB; default 8 log files; the log
files' suffix will be increased; when file count more than 8,
the last one added, the first one is removed, like form 1-8 to
2-9 to 3-10 ...
Tracked-On: #3012
Signed-off-by: Minggui Cao <minggui.cao@intel.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
