LU-11760 ofd: formatted OST recognition change

LU-11760 ofd: formatted OST recognition change

Modern system is fast enough to create above
100 000(5 * OST_MAX_PRECREATE) objects during commit interval.
Increase the difference between MDS last_used ID
and OST LAST_ID to 500 000 to avoid gaps after OST failover.

Cray-bug-id: LUS-6399
Change-Id: If36e04878d13f27f5229b488781440a159ddff7d
Signed-off-by: Sergey Cheremencev <c17829@cray.com>
Reviewed-on: https://es-gerrit.dev.cray.com/153866
Reviewed-by: Alexander Boyko <c17825@cray.com>
Reviewed-by: Alexander Zarochentsev <c17826@cray.com>
Tested-by: Elena Gryaznova <c17455@cray.com>
Reviewed-on: https://review.whamcloud.com/33833
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Alexandr Boyko <c17825@cray.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>