LU-6780 ptlrpc: Do not resend req with allow_replay

LU-6780 ptlrpc: Do not resend req with allow_replay

If the request is allowed to be sent during recovery,
and it is not timeout yet, then we do not need to
resend it in the final stage of recovery.

Unnecessary resend will cause the bulk request to resend the
request with different mbit, but same xid, and on the remote
server side, it will drop such request with same xid, so it
will never get the bulk in this case.

re-enable the multiple MDT failover cases in replay-single.sh

Signed-off-by: wang di <di.wang@intel.com>
Change-Id: I96900448fc16b0e2a336a42c8ff977ec56941427
Reviewed-on: http://review.whamcloud.com/15458
Tested-by: Jenkins
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Liang Zhen <liang.zhen@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>