LU-6465 osd: NO OI scrub because of cached invalid OI mapping

LU-6465 osd: NO OI scrub because of cached invalid OI mapping

On server side, the RPC service thread may cache one OI mapping
on its stack, such OI mapping will become invalid if some other
removed the object by race. If the RPC service thread uses the
cached OI mapping and finds some inconsistent object, it should
re-lookup the OI files to verify whether the OI mapping that is
cached on the stack is valid or not. If the OI mapping has been
removed from the OI file, then means the OI mapping is invalid,
should NOT trigger OI scrub under such case.

Signed-off-by: Fan Yong <fan.yong@intel.com>
Change-Id: Ifbc653fcc635d77447747f91de79bcc16f2dcbbc
Reviewed-on: http://review.whamcloud.com/14499
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: wangdi <di.wang@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>