staging: lustre: statahead: drop support for remote entry

This patch dropped support for remote entry statahead, because it
needs 2 async RPCs to fetch both LOOKUP lock from parent MDT and
UPDATE lock from client MDT, which is complicated. Plus not
supporting remote entry statahead won't cause any issue.

* pack child fid in statahead request.
* lmv_intent_getattr_async() will compare parent and child MDT,
  if child is remote, return -ENOTSUPP.

Signed-off-by: Lai Siyao <lai.siyao@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6578
Reviewed-on: http://review.whamcloud.com/15767


Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: wangdi <di.wang@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>