staging: lustre: ptlrpc: reset imp_replay_cursor

At client side, the replay cursor using to speed up the lookup
of committed open requests in its obd_import should be resetted
for normal connection (not reconnection) during recovery.

Signed-off-by: Hongchao Zhang <hongchao.zhang@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6802
Reviewed-on: http://review.whamcloud.com/17351


Reviewed-by: Niu Yawei <yawei.niu@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@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>