LU-4768 tests: Update ost-survey script

LU-4768 tests: Update ost-survey script

Currently, ost-survey hangs due to calling
'lfs setstripe' in an old (positional) style and
setting max_cached_mb to zero.

The call to 'lfs setstripe' is updated to use the
'-S', '-i' and '-c' flags. max_cached_mb is now
set to pagesize * 256 (in MB). The patch also gets
parameters for the correct file system if more
than one Lustre file system is mounted, and
corrects a few typos in comments.

In ll_max_cached_mb_seq_write(), the number of
pages requested is set to the max of pages requested
or PTLRPC_MAX_BRW_PAGES to allow the client to make
well formed RPCs.

Signed-off-by: James Nunez <james.a.nunez@intel.com>
Change-Id: Ib0adb0dc363a3b885d1566fda2ac3b9da013c238
Reviewed-on: http://review.whamcloud.com/11971
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Reviewed-by: Cliff White <cliff.white@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>