[rhythmbox] brasero-disc-recorder: Fix invalid object reference warnings

[Jonathan Matthew <jmatthew src gnome org>]

commit fbb6ad7fb04f02d83347c402e96d7a2b832a6d63
Author: gkrithi8 <gkrithi8 gmail com>
Date:   Thu Oct 26 02:27:38 2017 +0530

    brasero-disc-recorder: Fix invalid object reference warnings
    
    https://bugzilla.gnome.org/show_bug.cgi?id=789494

 .../rb-disc-recorder-plugin.c                      |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/plugins/brasero-disc-recorder/rb-disc-recorder-plugin.c 
b/plugins/brasero-disc-recorder/rb-disc-recorder-plugin.c
index 8608e84..a89d87a 100644
--- a/plugins/brasero-disc-recorder/rb-disc-recorder-plugin.c
+++ b/plugins/brasero-disc-recorder/rb-disc-recorder-plugin.c
@@ -558,7 +558,7 @@ update_source (RBDiscRecorderPlugin *pi,
        RBDisplayPage *selected_page;
        const char *page_type;
 
-       if (pi->selected_page != NULL && RB_IS_SOURCE (pi->selected_page)) {
+       if (pi->selected_page != NULL && RB_IS_PLAYLIST_SOURCE (pi->selected_page)) {
                RhythmDBQueryModel *model;
 
                g_object_get (pi->selected_page, "query-model", &model, NULL);