USB: class: cdc-acm: clean up urb->status usage

This done in anticipation of removal of urb->status, which will make
that patch easier to review and apply in the future.

Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/class/cdc-acm.c

···
 	struct usb_cdc_notification *dr = urb->transfer_buffer;
 	unsigned char *data;
 	int newctrl;
-	int status;
+	int retval;
+	int status = urb->status;
 
-	switch (urb->status) {
+	switch (status) {
 	case 0:
 		/* success */
 		break;
···
 	case -ENOENT:
 	case -ESHUTDOWN:
 		/* this urb is terminated, clean up */
-		dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
+		dbg("%s - urb shutting down with status: %d", __FUNCTION__, status);
 		return;
 	default:
-		dbg("%s - nonzero urb status received: %d", __FUNCTION__, urb->status);
+		dbg("%s - nonzero urb status received: %d", __FUNCTION__, status);
 		goto exit;
 	}
 
···
 			break;
 	}
 exit:
-	status = usb_submit_urb (urb, GFP_ATOMIC);
-	if (status)
+	retval = usb_submit_urb (urb, GFP_ATOMIC);
+	if (retval)
 		err ("%s - usb_submit_urb failed with result %d",
-		     __FUNCTION__, status);
+		     __FUNCTION__, retval);
 }
 
 /* data interface returns incoming bytes, or we got unthrottled */
···
 	struct acm_ru *rcv = urb->context;
 	struct acm *acm = rcv->instance;
 	int status = urb->status;
-	dbg("Entering acm_read_bulk with status %d", urb->status);
+
+	dbg("Entering acm_read_bulk with status %d", status);
 
 	if (!ACM_READY(acm))
 		return;