LU-10824 llite: don't use ll_mnt to get fstype name

LU-10824 llite: don't use ll_mnt to get fstype name

Originally lustre would report using the fstype proc file either
'lustre' or 'llite'. This required us to query struct super_block
but its been a very long time since that is the case. This also
removes a direct use of ll_mnt. The fix is simply report 'lustre'.

Test-Parameters: trivial

Change-Id: Ia766c8e0a027e58a48de8fa6e2756238e20312b2
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/33025
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>