LU-2524 tests: clean up conf-sanity test_38 for ZFS

LU-2524 tests: clean up conf-sanity test_38 for ZFS

Clean up conf-sanity.sh test_38 so that it mounts the filesystem
locally instead of using debugfs.  That allows it to be run on
ZFS instead of being skipped.  Other minor style fixes.

Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: I68090d2082b298b81518e5ffde847f15b47953b4
Reviewed-on: http://review.whamcloud.com/9184
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Reviewed-by: Isaac Huang <he.huang@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>