USB: serial: omninet: simplify endpoint check

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.

Note that the driver uses the second bulk-out endpoint for writing.
Signed-off-by: Johan Hovold <johan@kernel.org>

drivers/usb/serial/omninet.c

@@ -37,7 +37,6 @@ static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
 				const unsigned char *buf, int count);
 static int  omninet_write_room(struct tty_struct *tty);
 static void omninet_disconnect(struct usb_serial *serial);
-static int omninet_attach(struct usb_serial *serial);
 static int omninet_port_probe(struct usb_serial_port *port);
 static int omninet_port_remove(struct usb_serial_port *port);
 
@@ -56,7 +55,7 @@ static struct usb_serial_driver zyxel_omninet_device = {
 	.description =		"ZyXEL - omni.net lcd plus usb",
 	.id_table =		id_table,
 	.num_ports =		1,
-	.attach =		omninet_attach,
+	.num_bulk_out =		2,
 	.port_probe =		omninet_port_probe,
 	.port_remove =		omninet_port_remove,
 	.write =		omninet_write,
@@ -104,17 +103,6 @@ struct omninet_data {
 	__u8	od_outseq;	/* Sequence number for bulk_out URBs */
 };
 
-static int omninet_attach(struct usb_serial *serial)
-{
-	/* The second bulk-out endpoint is used for writing. */
-	if (serial->num_bulk_out < 2) {
-		dev_err(&serial->interface->dev, "missing endpoints\n");
-		return -ENODEV;
-	}
-
-	return 0;
-}
-
 static int omninet_port_probe(struct usb_serial_port *port)
 {
 	struct omninet_data *od;