LU-7702 ldlm: skip lock if export failed

LU-7702 ldlm: skip lock if export failed

This patch resolves IO vs eviction race.
After eviction failed export stayed at stale list,
a client had IO processing and reconnected during it.
A client sent brw rpc with last lock cookie and new connection.
The lock with failed export was found and assert was happened.
(ost_handler.c:1812:ost_prolong_lock_one())
	ASSERTION( lock->l_export == opd->opd_exp ) failed:

1. Skip the lock at ldlm_handle2lock if lock export failed.
2. Validation of lock for IO was added at hpreq_check(). The lock
   searching is based on granted interval tree. If server doesn`t
   have a valid lock, it reply to client with ESTALE.
3. A lock prolong was moved at ldlm layer.

Signed-off-by: Alexander Boyko <alexander.boyko@seagate.com>
Seagate-bug-id: MRP-2787
Change-Id: I2177736564c3b8164f1ad3e4cc02dca1704a0e6e
Reviewed-on: http://review.whamcloud.com/18120
Reviewed-by: Fan Yong <fan.yong@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Vitaly Fertman <vitaly.fertman@seagate.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>