staging/lustre/scrub: purge inconsistenct objects after OI scrub

When OI scrub repaired the found inconsistency, it needs to purge the
old object out of cache; otherwise, others may still use those cached
stale information.

Original patch adds functions in obdclass that is only used by server.
Drop that part. Only merge in error handling change.

Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3335
Lustre-change: http://review.whamcloud.com/6697


Signed-off-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>