discover/network: Search by UUID only if available

When registering a new discover device it is possible the device does
not have an associated UUID, for example when created via
device_handler_process_url(). Fall back to find_interface_by_name() in
this case.

Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>

discover/network.c

@@ -242,7 +242,10 @@ void network_register_device(struct network *network,
 {
 	struct interface *iface;
 
-	iface = find_interface_by_uuid(network, dev->uuid);
+	if (dev->uuid)
+		iface = find_interface_by_uuid(network, dev->uuid);
+	else
+		iface = find_interface_by_name(network, dev->label);
 	if (!iface)
 		return;