In vnet_create_sw_interface function if there's an error in calling vnet_sw_interface_set_flags_helper, we should also call call_sw_interface_add_del_callbacks. because although we haven't called callbacks in creating SW interface, but they are called in set flag helper function.

To reproduce this issue, just make a subinterface on an interface with tag X. Then try to make another subinterface for the same interface with the same tag X but a different instance. It all goes well up until it calls the interface add/del callback ethernet_sw_interface_add_del. At this point the function fails and SW interface is removed from pool but if we have other callback functions that are called successfully before ethernet_sw_interface_add_del __ they are not informed.