[PATCH 3/4] Docs: usb: update comment and code of function skel_delete

[Philipp Hortmann <philipp.g.hortmann@gmail.com>]

Put skel_delete function in the document typical form
Update code according to usb-skeleton.c

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
---
 .../driver-api/usb/writing_usb_driver.rst     | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/Documentation/driver-api/usb/writing_usb_driver.rst b/Documentation/driver-api/usb/writing_usb_driver.rst
index b16e4e76d472..74bb72a2f0ac 100644
--- a/Documentation/driver-api/usb/writing_usb_driver.rst
+++ b/Documentation/driver-api/usb/writing_usb_driver.rst
@@ -263,18 +263,17 @@ handle smoothly is the fact that the USB device may be removed from the
 system at any point in time, even if a program is currently talking to
 it. It needs to be able to shut down any current reads and writes and
 notify the user-space programs that the device is no longer there. The
-following code (function ``skel_delete``) is an example of how to do
-this::
+`skel_delete` function is an example of how to do this::
 
-    static inline void skel_delete (struct usb_skel *dev)
+    static void skel_delete(struct kref *kref)
     {
-	kfree (dev->bulk_in_buffer);
-	if (dev->bulk_out_buffer != NULL)
-	    usb_free_coherent (dev->udev, dev->bulk_out_size,
-		dev->bulk_out_buffer,
-		dev->write_urb->transfer_dma);
-	usb_free_urb (dev->write_urb);
-	kfree (dev);
+	struct usb_skel *dev = to_skel_dev(kref);
+
+	usb_free_urb(dev->bulk_in_urb);
+	usb_put_intf(dev->interface);
+	usb_put_dev(dev->udev);
+	kfree(dev->bulk_in_buffer);
+	kfree(dev);
     }
 
 
-- 
2.25.1