driver core: fix docbook for device_private.device
driver core: fix docbook for device_private.device

This field refers to the public device struct, not to classes.

Signed-off-by: Tomeu Vizoso <8b6d03f77639b596ee6a2bb7aebb412be798513b@collabora.com>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs