Remove faulty free in GetDescDocumentAndURL.

temp_str, which points to part of description, should not be freed.
(cherry picked from commit f6a3102b487f415895a95a0554ae66b092333c79)
Fix return value of config_description_doc.

UPNP_E_XXX should not be used instead of IXML_XXX
(cherry picked from commit 72c29ef1f6f4ba544f4a1a6d97428becca940301)