Incorrect code examples in form_process_text_format()

While reviewing #11218: Allow default text formats per role, and integrate text format permissions, @dropcube pointed out that the examples in the code documentation of http://api.drupal.org/api/function/form_process_text_format/7 are out of date, since they assume that the node body/format is part of the node itself, rather than using the Field API as it does now.

However, given that #414424: Introduce Form API #type 'text_format' is filed as a critical bug against D7, this whole function might not exist by the time D7 is released anyway, so maybe it's not worth fixing...