AP_Notify: change class name from SITL::SITL to SITL::SIM

libraries/AP_Notify/SITL_SFML_LED.cpp

@@ -119,7 +119,7 @@ void SITL_SFML_LED::update_serial_LEDs()
     static sf::RenderWindow *w;
     static sf::RectangleShape *leds[16][MAX_LEDS];
 
-    SITL::SITL *sitl = AP::sitl();
+    SITL::SIM *sitl = AP::sitl();
     if (sitl == nullptr || sitl->led.send_counter == 0) {
         // no SerialLEDs set
         return;