interfaces: make no_flatten variant of inteface_ouptut fn default

Flatten variant was used only by old native drivers.

Change-Id: If206c6c8b4f10843d60f908c3acb4e8db83ce03d
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/vnet/vnet/interface.h b/vnet/vnet/interface.h
index d3076a5..b5245e4 100644
--- a/vnet/vnet/interface.h
+++ b/vnet/vnet/interface.h
@@ -180,8 +180,8 @@
   /* Link-list of all device classes set up by constructors created below */
   struct _vnet_device_class *next_class_registration;
 
-  /* Do not splice vnet_interface_output_node into TX path */
-  u8 no_flatten_output_chains;
+  /* Splice vnet_interface_output_node into TX path */
+  u8 flatten_output_chains;
 
   /* Function to set mac address. */
   vnet_interface_set_mac_address_function_t *mac_addr_change_function;