udevd: netif rename - use ifindex for temporary name

TODO

@@ -1,7 +1,5 @@
   - empty rules files and link to /dev/null are ok
 
-  - rename netif with ifindex not devname
-
   - kill tabs?
 
   - remove deprecated trigger --type=failed logic

udev/udev-event.c

@@ -868,7 +868,7 @@ static int rename_netif(struct udev_event *event)
 		goto out;
 
 	/* free our own name, another process may wait for us */
-	util_strscpyl(ifr.ifr_newname, IFNAMSIZ, udev_device_get_sysname(dev), "-", event->name, NULL);
+	snprintf(ifr.ifr_newname, IFNAMSIZ, "rename%u", udev_device_get_ifindex(dev));
 	err = ioctl(sk, SIOCSIFNAME, &ifr);
 	if (err < 0) {
 		err = -errno;