Fix potential problem with AnnotationIntrospectorPair, findSerializer(), findDeserializer() #1581
Description
(note: offshoot of FasterXML/jackson-dataformats-binary#69)
It appears there may be an issue with logic used by AnnotationIntrospectorPair with findSerializer(), findDeserializer(), which prevents returning of actual ser/deser instance, instead of Class.
If so, fix it to work as expected.