-"empty" release function; you will be mocked mercilessly by the kobject
-maintainer if you attempt this.
+"empty" release function.
+
+If all your cleanup function needs to do is call kfree(), then you must
+create a wrapper function which uses container_of() to upcast to the correct
+type (as shown in the example above) and then calls kfree() on the overall
+structure.