LU-2154 osp: precreate logic to use last assigned id

LU-2154 osp: precreate logic to use last assigned id

instead of "next to assign". this change removes few cases
where last-created-id could become less than next-to-assign
resulting in an invalid assertions.

Signed-off-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Change-Id: If41563ea2f227ea980e3017d9485cb9c7caccad5
Reviewed-on: http://review.whamcloud.com/4289
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Mike Pershin <tappro@whamcloud.com>