LU-4743 osp: continue llog processing

when unexpected record type is met

Signed-off-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Change-Id: I3dd45f501192bc6dd3bfddb550fd455ae319b923
Reviewed-on: http://review.whamcloud.com/9574
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Faccini Bruno <bruno.faccini@intel.com>