[retro-gtk] Make DiskControl private

[Adrien Plazas <aplazas src gnome org>]

commit ff90fcec531f8c98f6dc0afe9ff2e78476197e82
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Sun Jul 30 12:54:16 2017 +0100

    Make DiskControl private
    
    This helps reducing the public API as it is now only used internally.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=777489

 retro-gtk/disk-controller.vala |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/retro-gtk/disk-controller.vala b/retro-gtk/disk-controller.vala
index 71dd8ca..ce407fd 100644
--- a/retro-gtk/disk-controller.vala
+++ b/retro-gtk/disk-controller.vala
@@ -17,7 +17,7 @@ namespace Retro {
  *  * set the image index to the one you want to use.
  *  * insert the disk again by setting the eject state to false.
  */
-public class DiskControl: Object {
+private class DiskControl: Object {
        private weak Core core;
 
        private DiskControlCallback callback_struct;