LU-5241 tests: speed up sanity-lfsck and sanity-scrub tests

LU-5241 tests: speed up sanity-lfsck and sanity-scrub tests

1) drop unnecessary devices reformat.
2) drop unnecessary system stop/re-start.
3) replace 'sleep' with wait_update_facet to avoid idle wait.
4) drop unnecessary "-p" option for some "mkdir" cases.
5) replace "touch" with "createmany -m".
6) other code style changes and cleanup.

This patch is back-ported from the following one:
Lustre-commit: 1dbba329174e6c7f7712f01fc4e44c44400fbc92
Lustre-change: http://review.whamcloud.com/9704

LU-4803 ofd: skip orphan cleanup when inject OI error

When inject OI error for simulating some failure cases, the object
may be mapped to invalid local target (inode for ldiskfs), so skip
the orphan cleanup in OSP to avoid unexpected warning or destroy.

Lustre-commit: 0bafbd7d8f652997d83b3cc2419894f48833f424
Lustre-change: http://review.whamcloud.com/9759

Test-Parameters: alwaysuploadlogs envdefinitions=SLOW=yes \
testlist=lfsck-performance,sanity-scrub,sanity-lfsck

Signed-off-by: Fan Yong <fan.yong@intel.com>
Signed-off-by: Emoly Liu <emoly.liu@intel.com>
Change-Id: Iacae0047a502e3baa778b86536220d70c717f6f5
Reviewed-on: http://review.whamcloud.com/10818
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>