LU-4939 obdclass: llog_print params file

Allow llog_print to handle the params file in yaml

Lustre-commit: 320e736191cce766cd0838ebbd5e76f1aefa1a6f
Lustre-change: https://review.whamcloud.com/31620

Test-Parameters: trivial testlist=sanity
Signed-off-by: Ben Evans <bevans@cray.com>
Change-Id: Icf286bca7a1466bf3c8d9084971e58d2e8b8a651
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/34250
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>