scsi: qla2xxx: Remove unneeded flush_workqueue()

All work currently pending will be done first by calling
destroy_workqueue(). There is no need to flush it explicitly.

Link: https://lore.kernel.org/r/20220424062413.3220315-1-ran.jianping@zte.com.cn
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: ran jianping <ran.jianping@zte.com.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_os.c

@@ -3933,7 +3933,6 @@ qla2x00_free_device(scsi_qla_host_t *vha)
 
 	/* Flush the work queue and remove it */
 	if (ha->wq) {
-		flush_workqueue(ha->wq);
 		destroy_workqueue(ha->wq);
 		ha->wq = NULL;
 	}