LU-8066 llite: move /proc/fs/lustre/llite/stats_track* to

LU-8066 llite: move /proc/fs/lustre/llite/stats_track* to
 sysfs

Move stats_track_pid, stats_track_ppid and stats_track_gid files
from /proc/fs/lustre/llite/* to /sys/fs/lustre/llite/*/

This is a modified version of

Linux-commit: 62cf4b1315e86a1f373f77acf32a23d76428ba27

due to the large amount of changes to the OpenSFS/Intel branch.

Test-Parameters: trivial

Change-Id: I29dc2dd269f66e40a7d016ba366353ae2ca7fb51
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/32503
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Ben Evans <bevans@cray.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>