/* Endpoint TX buffer release callback for nocopy sending.  */
static int drop_tx_buffer(const struct device *instance, void *token, const void *data)
/* Endpoint TX buffer release callback for nocopy sending.  */
static int drop_tx_buffer(const struct device *instance, void *token, const void *data)
{
	struct backend_data *dev_data = instance->data;
	int r;
	r =  release_tx_buffer(dev_data, data, -1);
	if (r < 0) {
		return r;
	}
	return 0;
}