LUDOC-292 fix: Update formatting error in file path

LUDOC-292 fix: Update formatting error in file path

At some point the following line was changed in the
Visualizing Results section of the benchmarking section of
the manual:

/proc/fs/lustre/obdfilter/*/brw_stats

was accidentally changed to:

/proc/fs/lustre/obdfilter/

Also, "*/brw_stats" appeared in a <screen> tag, which was not
the intent.

The patch also updates these 3 paragraph for 80 character max
per line.

Signed-off-by: Joseph Gmitter <joseph.gmitter@intel.com>
Change-Id: I10f2a40cd06ee2403c8cb1545302e4c3da03a3b2
Reviewed-on: https://review.whamcloud.com/24200
Tested-by: Jenkins