blacklist: break earlier if hardcoded blacklist

src/gl/gl_hud.cpp

@@ -72,6 +72,9 @@ void imgui_init()
         return;
 
     init_spdlog();
+    if (is_blacklisted())
+        return;
+
     parse_overlay_config(&params, getenv("MANGOHUD_CONFIG"));
     _params = &params;
 

src/vulkan.cpp

@@ -1893,6 +1893,9 @@ static VkResult overlay_CreateInstance(
                              &instance_data->vtable);
    instance_data_map_physical_devices(instance_data, true);
 
+   if (is_blacklisted())
+      return result;
+
    parse_overlay_config(&instance_data->params, getenv("MANGOHUD_CONFIG"));
    _params = &instance_data->params;