fix incorrect attribute name in check_data_types (cf.py)
fix incorrect attribute name in check_data_types (cf.py)

ocefpaf/compliance-checker,DanielJMaher/compliance-checker,ioos/compliance-checker,lukecampbell/compliance-checker,webtrike/compliance-checker,duncombe/compliance-checker,aodn/compliance-checker,petejan/compliance-checker,abirger/compliance-checker