LU-4690 osp: some cleanup for patch 9511

cleanup patch 9511 according to the review

1. fix endian problem in osd-zfs and osp.
2. Few tab and typo fixes.
3. move mti_big_lmm_used back to mdt_stripe_get,
set it in mdt_big_xattr_get is a bit risky.

Signed-off-by: wang di <di.wang@intel.com>
Change-Id: I85982bf198dddc9e0442e392f3da25cca46dfe03
Reviewed-on: http://review.whamcloud.com/10261
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>