libertas_usb: use USB interface as parent device

Currently, "udevadm info -a -p /sys/class/net/wlan0" doesn't mention
the usb8xxx or libertas driver anywhere. This makes writing udev rules
a bit uncomfortable.

Using the USB interface as the parent device corrects the hierarchy.
Signed-off-by: Daniel Drake <dsd@laptop.org>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/if_usb.c

@@ -324,7 +324,7 @@ static int if_usb_probe(struct usb_interface *intf,
 	}
 	kparam_unblock_sysfs_write(fw_name);
 
-	if (!(priv = lbs_add_card(cardp, &udev->dev)))
+	if (!(priv = lbs_add_card(cardp, &intf->dev)))
 		goto err_prog_firmware;
 
 	cardp->priv = priv;