Use getKnownValue()

Author: web-flow

lib/checkbufferoverrun.cpp

@@ -646,7 +646,9 @@ static bool checkBufferSize(const Token *ftok, const Library::ArgumentChecks::Mi
         break;
     case Library::ArgumentChecks::MinSize::Type::ARGVALUE: {
         if (arg) {
-            const ValueFlow::Value* argVal = arg->hasKnownIntValue() ? &arg->values().front() : arg->getMaxValue(true);
+            const ValueFlow::Value* argVal = arg->hasKnownIntValue() ?
+                arg->getKnownValue(ValueFlow::Value::ValueType::INT) :
+                arg->getMaxValue(/*condition*/ true);
             if (!argVal)
                 break;
             MathLib::bigint myMinsize = argVal->intvalue;