There is no audit checklist for ISO 22000 available here on the Cove, but various threads have been started on the subject... specifically on checklists...
As previously discussed in other forums regarding other standards and pre-ready checklists, it´s best to develop your own, based on your needs, requirements and specifics... read the standard, analyze your system and develop the questions you want to see answered... (this is basically what is said in the attached post).