df2ddc9e7e
reference counting of ns_interface objects has not been used since the clientmgr cleanup in #2433, and it no longer really makes sense now - when we want to destroy an interface on a rescan, we want it to be destroyed, not kept active by some other caller. so ns_interface_attach() has been removed, ns_interface_detach() has been replaced with a static interface_destroy(), and do_scan() has been simplified accordingly.