avoid unnecessary std::istringstream usage with picojson

Author: firewave

lib/addoninfo.cpp

@@ -93,9 +93,8 @@ static std::string parseAddonInfo(AddonInfo& addoninfo, const picojson::value &j
 
 std::string AddonInfo::getAddonInfo(const std::string &fileName, const std::string &exename) {
     if (fileName[0] == '{') {
-        std::istringstream in(fileName);
         picojson::value json;
-        in >> json;
+        picojson::parse(json, fileName);
         return parseAddonInfo(*this, json, fileName, exename);
     }
     if (fileName.find('.') == std::string::npos)

lib/cppcheck.cpp

@@ -1350,8 +1350,7 @@ void CppCheck::executeAddons(const std::vector<std::string>& files)
                 continue;
 
             picojson::value res;
-            std::istringstream istr2(line);
-            istr2 >> res;
+            picojson::parse(res, line);
             if (!res.is<picojson::object>())
                 continue;