LU-5223 lod: generate linkEA for shard of striped directory

LU-5223 lod: generate linkEA for shard of striped directory

Otherwise, it will misguide namespace LFSCK to regard it as the case
of linkEA corrupted or upgraded from 1.8 device, then cause improper
reparing or status reporting.

On the other hand, the linkEA for slave object of striped directory
will also be used for fid2path in subsequent patches.

Signed-off-by: Fan Yong <fan.yong@intel.com>
Change-Id: I877b091eb330df0283de2ea21f2796387023da30
Reviewed-on: http://review.whamcloud.com/10765
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: wangdi <di.wang@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>