USB: serial: opticon: simplify endpoint check

Simplify the endpoint sanity check by letting core verify that the
required endpoints are present.
Signed-off-by: Johan Hovold <johan@kernel.org>

drivers/usb/serial/opticon.c

@@ -367,16 +367,6 @@ static int opticon_ioctl(struct tty_struct *tty,
 	return -ENOIOCTLCMD;
 }
 
-static int opticon_startup(struct usb_serial *serial)
-{
-	if (!serial->num_bulk_in) {
-		dev_err(&serial->dev->dev, "no bulk in endpoint\n");
-		return -ENODEV;
-	}
-
-	return 0;
-}
-
 static int opticon_port_probe(struct usb_serial_port *port)
 {
 	struct opticon_private *priv;
@@ -408,8 +398,8 @@ static struct usb_serial_driver opticon_device = {
 	},
 	.id_table =		id_table,
 	.num_ports =		1,
+	.num_bulk_in =		1,
 	.bulk_in_size =		256,
-	.attach =		opticon_startup,
 	.port_probe =		opticon_port_probe,
 	.port_remove =		opticon_port_remove,
 	.open =			opticon_open,