i2c: diolan-u2c: drop redundant device reference

Driver core holds a reference to the USB interface and its parent USB
device while the interface is bound to a driver and there is no need to
take additional references unless the structures are needed after
disconnect.

Drop the redundant device reference to reduce cargo culting, make it
easier to spot drivers where an extra reference is needed, and reduce
the risk of memory leaks when drivers fail to release it.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Author: jhovold

drivers/i2c/busses/i2c-diolan-u2c.c

@@ -427,12 +427,6 @@ static const struct usb_device_id diolan_u2c_table[] = {
 
 MODULE_DEVICE_TABLE(usb, diolan_u2c_table);
 
-static void diolan_u2c_free(struct i2c_diolan_u2c *dev)
-{
-	usb_put_dev(dev->usb_dev);
-	kfree(dev);
-}
-
 static int diolan_u2c_probe(struct usb_interface *interface,
 			    const struct usb_device_id *id)
 {
@@ -453,7 +447,7 @@ static int diolan_u2c_probe(struct usb_interface *interface,
 	dev->ep_out = hostif->endpoint[0].desc.bEndpointAddress;
 	dev->ep_in = hostif->endpoint[1].desc.bEndpointAddress;
 
-	dev->usb_dev = usb_get_dev(interface_to_usbdev(interface));
+	dev->usb_dev = interface_to_usbdev(interface);
 	dev->interface = interface;
 
 	/* save our data pointer in this interface device */
@@ -488,7 +482,7 @@ static int diolan_u2c_probe(struct usb_interface *interface,
 
 error_free:
 	usb_set_intfdata(interface, NULL);
-	diolan_u2c_free(dev);
+	kfree(dev);
 error:
 	return ret;
 }
@@ -499,7 +493,7 @@ static void diolan_u2c_disconnect(struct usb_interface *interface)
 
 	i2c_del_adapter(&dev->adapter);
 	usb_set_intfdata(interface, NULL);
-	diolan_u2c_free(dev);
+	kfree(dev);
 
 	dev_dbg(&interface->dev, "disconnected\n");
 }