[gtk] glarea: Fix buffer initialization

[Timm Bäder <baedert src gnome org>]

commit b9473bc99c0bf658558e575243de219d0d02d237
Author: Timm Bäder <mail baedert org>
Date:   Wed Aug 28 10:05:48 2019 +0200

    glarea: Fix buffer initialization
    
    This only worked when the vao id and the buffer id accidentally matched,
    for example when running gtk4-demo with --run=glarea
    
    Fixes #2042

 demos/gtk-demo/glarea.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/demos/gtk-demo/glarea.c b/demos/gtk-demo/glarea.c
index eed1e80ec3..21e88b63ae 100644
--- a/demos/gtk-demo/glarea.c
+++ b/demos/gtk-demo/glarea.c
@@ -241,7 +241,7 @@ realize (GtkWidget *widget)
       fragment_path = "/glarea/glarea-gl.fs.glsl";
     }
 
-  init_buffers (&position_buffer, NULL);
+  init_buffers (NULL, &position_buffer);
   init_shaders (vertex_path, fragment_path, &program, &mvp_location);
 }