LU-6996 osd-ldiskfs: handle stale OI mapping cache

LU-6996 osd-ldiskfs: handle stale OI mapping cache

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 the inode that has been unlinked
and reused by other object with no LMA generated yet, then
the osd_check_lma() should NOT skip such case to avoid the
caller mis-using the inode by wrong.

Signed-off-by: Fan Yong <fan.yong@intel.com>
Change-Id: I46348a06327bcf944aff9af7914230573e2cef89
Reviewed-on: http://review.whamcloud.com/16157
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>