USB: cypress_cy7c63: convert to use dev_groups

USB drivers now support the ability for the driver core to handle the
creation and removal of device-specific sysfs files in a race-free
manner. Take advantage of that by converting the driver to use this by
moving the sysfs attributes into a group and assigning the dev_groups
pointer to it.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/misc/cypress_cy7c63.c

···
 {
 	return read_port(dev, attr, buf, 0, CYPRESS_READ_PORT_ID0);
 }
+static DEVICE_ATTR_RW(port0);
 
 /* attribute callback handler (read) */
 static ssize_t port1_show(struct device *dev,
···
 {
 	return read_port(dev, attr, buf, 1, CYPRESS_READ_PORT_ID1);
 }
-
-static DEVICE_ATTR_RW(port0);
-
 static DEVICE_ATTR_RW(port1);
 
+static struct attribute *cypress_attrs[] = {
+	&dev_attr_port0.attr,
+	&dev_attr_port1.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(cypress);
 
 static int cypress_probe(struct usb_interface *interface,
 			 const struct usb_device_id *id)
···
 	/* save our data pointer in this interface device */
 	usb_set_intfdata(interface, dev);
 
-	/* create device attribute files */
-	retval = device_create_file(&interface->dev, &dev_attr_port0);
-	if (retval)
-		goto error;
-	retval = device_create_file(&interface->dev, &dev_attr_port1);
-	if (retval)
-		goto error;
-
 	/* let the user know that the device is now attached */
 	dev_info(&interface->dev,
 		 "Cypress CY7C63xxx device now attached\n");
 	return 0;
-
-error:
-	device_remove_file(&interface->dev, &dev_attr_port0);
-	device_remove_file(&interface->dev, &dev_attr_port1);
-	usb_set_intfdata(interface, NULL);
-	usb_put_dev(dev->udev);
-	kfree(dev);
 
 error_mem:
 	return retval;
···
 
 	dev = usb_get_intfdata(interface);
 
-	/* remove device attribute files */
-	device_remove_file(&interface->dev, &dev_attr_port0);
-	device_remove_file(&interface->dev, &dev_attr_port1);
 	/* the intfdata can be set to NULL only after the
 	 * device files have been removed */
 	usb_set_intfdata(interface, NULL);
···
 	.probe = cypress_probe,
 	.disconnect = cypress_disconnect,
 	.id_table = cypress_table,
+	.dev_groups = cypress_groups,
 };
 
 module_usb_driver(cypress_driver);