LU-3110 tests: OSD_TRACK_DECLARES_LBUG default & handling

LU-3110 tests: OSD_TRACK_DECLARES_LBUG default & handling

This patch sets OSD_TRACK_DECLARES_LBUG as yes/on by
default in Tests and also implements its correct
handling to only apply it on servers running with
ldiskfs back-end.

Signed-off-by: Bruno Faccini <bruno.faccini@intel.com>
Change-Id: Ie1764a3a576809f9f913f6effc54965a3bd153dc
Reviewed-on: http://review.whamcloud.com/6280
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>