scsi: qla2xxx: Chip reset uses wrong lock during IO flush.

As part of chip reset, all commands from all QPairs are
flushed. This patch fixes code to use Q Pair lock for flush
instead of using old hardware_lock.

Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>