remove call to convert() on return value of process method for inline…

… macro extension (#1653)

- the process method should return an Inline object, not a string

docs/modules/extend/examples/extensions/emoticon-inline-macro-processor.js

@@ -10,7 +10,7 @@ module.exports = function (registry) {
       } else {
         text = ':)'
       }
-      return self.createInline(parent, 'quoted', text, { 'type': 'strong' }).convert()
+      return self.createInline(parent, 'quoted', text, { 'type': 'strong' })
     })
   })
 }