LU-5843 tests: fix recovery-small test_61

LU-5843 tests: fix recovery-small test_61

Test used obdfilter last_id as number while it is OID,
e.g. 0x100000000:16. Patch fixes test to exract object ID
from OID.

Signed-off-by: Mikhail Pershin <mike.pershin@intel.com>
Change-Id: If921cf41253450ab035a75be6fb34145aee1a197
Reviewed-on: http://review.whamcloud.com/12653
Tested-by: Jenkins
Reviewed-by: Li Wei <wei.g.li@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>