USB: fix cdc-acm resume()

cdc-acm has
- a memory leak in resume()
- will fail to reactivate the read code path if this is needed.
his corrects it by deleting the useless relict code.
Signed-off-by: NOliver Neukum <oneukum@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/class/cdc-acm.c

@@ -1125,9 +1125,6 @@ static void stop_data_traffic(struct acm *acm)
 	for (i = 0; i < acm->rx_buflimit; i++)
 		usb_kill_urb(acm->ru[i].urb);
 
-	INIT_LIST_HEAD(&acm->filled_read_bufs);
-	INIT_LIST_HEAD(&acm->spare_read_bufs);
-
 	tasklet_enable(&acm->urb_task);
 
 	cancel_work_sync(&acm->work);