Merge "usb: f_serial: Check port_num before allocating serial instance"

	struct f_gser	*gser;

	struct f_serial_opts *opts;

	opts = container_of(fi, struct f_serial_opts, func_inst);

	if (nr_ports) {

		opts->port_num = gser_next_free_port++;

		if (opts->port_num >= GSERIAL_NO_PORTS) {

			pr_err("%s: No serial allowed for port %d\n",

					__func__, opts->port_num);

			return ERR_PTR(-EINVAL);

		}

	}

	/* allocate and initialize one new instance */

	gser = kzalloc(sizeof(*gser), GFP_KERNEL);

	if (!gser)

		return ERR_PTR(-ENOMEM);

	opts = container_of(fi, struct f_serial_opts, func_inst);

	spin_lock_init(&gser->lock);

	if (nr_ports)

		opts->port_num = gser_next_free_port++;

	gser->port_num = opts->port_num;

	gser->port.func.name = "gser";