In interface_removed function, connman_device_set_powered may not be
called due to wifi->device is freed before supplicant callback. This
happens when we remove the second wifi device. This may lead technology
refcount inbalance, which could potentially prevent the wifi technology to
be enabled again.
remove_networks(device, wifi);
+ connman_device_set_powered(device, FALSE);
connman_device_set_data(device, NULL);
connman_device_unref(wifi->device);
connman_rtnl_remove_watch(wifi->watch);