change the returned value (open-source-parsers#1003)

Author: dota17

src/lib_json/json_reader.cpp

@@ -311,7 +311,7 @@ bool Reader::readToken(Token& token) {
   if (!ok)
     token.type_ = tokenError;
   token.end_ = current_;
-  return true;
+  return ok;
 }
 
 void Reader::skipSpaces() {
@@ -1274,7 +1274,7 @@ bool OurReader::readToken(Token& token) {
   if (!ok)
     token.type_ = tokenError;
   token.end_ = current_;
-  return true;
+  return ok;
 }
 
 void OurReader::skipSpaces() {