USB: misc: appledisplay: 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/misc/appledisplay.c

···
 {
 	struct appledisplay *pdata = urb->context;
 	unsigned long flags;
+	int status = urb->status;
 	int retval;
 
-	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 shuttingdown with status: %d",
+			__FUNCTION__, status);
 		return;
 	default:
 		dbg("%s - nonzero urb status received: %d",
-			__FUNCTION__, urb->status);
+			__FUNCTION__, status);
 		goto exit;
 	}