LU-10028 obdclass: Export Lustre mount flags and options

LU-10028 obdclass: Export Lustre mount flags and options

This patch help to export the information about Lustre special
mount flags and options via '/proc/mounts'.

The output for Lustre mounts by '/proc/mounts' is:
/dev/loop0 /mnt/lustre-mds1 lustre ro,svname=lustre-MDT0000,
mgs,osd=osd-ldiskfs,user_xattr,errors=remount-ro 0 0
/dev/loop1 /mnt/lustre-ost1 lustre ro,svname=lustre-OST0000,
mgsnode=192.168.59.129@tcp,osd=osd-ldiskfs,errors=remount-ro 0 0
/dev/loop2 /mnt/lustre-ost2 lustre ro,svname=lustre-OST0001,
mgsnode=192.168.59.129@tcp,osd=osd-ldiskfs,errors=remount-ro 0 0
192.168.59.129@tcp:/lustre /mnt/lustre lustre rw,flock,
user_xattr,lazystatfs 0 0

Signed-off-by: Qian Yingjin <qian@ddn.com>
Change-Id: I6cdbcaf4fd5a6a3621ed675b1c4485073e774d8c
Reviewed-on: https://review.whamcloud.com/29228
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>