Fix OCSP response error/status parsing
Fix OCSP response error/status parsing

While working on the ocspresponder project I realized that I'd gone
wildly wrong in trying to handle scenario statuses from the OCSP
library.  This change uses the API (hopefully) correctly and stops
"happening to work because 0 in underlying int is good/success in each
case".

PennockTech/smtpdane,PennockTech/smtpdane