LU-5651: ptlrpc: fix import state during replay

LU-5651: ptlrpc: fix import state during replay

Client doesn't restore import state correctly
on reconnect during replay. It resends lock replay
when final ping was queued by server.
Server fails with "target_queue_recovery_request())
ASSERTION( req->rq_export->exp_lock_replay_needed ) failed"

Add imp_replay_state to store last replay state.
imp_state is restored from imp_replay_state
during reconnect.

Xyratex-bug-id: MRP-2022
Signed-off-by: Andriy Skulysh <Andriy_Skulysh@xyratex.com>
Change-Id: Iaa14fe968cc31f266b605785df4fa676083fbca4
Reviewed-on: http://review.whamcloud.com/12015
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Niu Yawei <yawei.niu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>