[brasero] Fix wrong value of a member after unref

[Philippe Rouquier <philippr src gnome org>]

commit f757166c7d3380fd5fb4b4314ad36811bfae50d2
Author: Philippe Rouquier <bonfire-app wanadoo fr>
Date:   Tue Jul 28 15:24:48 2009 +0200

    Fix wrong value of a member after unref

 libbrasero-burn/brasero-dest-selection.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/libbrasero-burn/brasero-dest-selection.c b/libbrasero-burn/brasero-dest-selection.c
index e6f7a41..752f0e8 100644
--- a/libbrasero-burn/brasero-dest-selection.c
+++ b/libbrasero-burn/brasero-dest-selection.c
@@ -223,6 +223,7 @@ brasero_dest_selection_clean (BraseroDestSelection *self)
 	if (priv->locked_drive) {
 		brasero_drive_unlock (priv->locked_drive);
 		g_object_unref (priv->locked_drive);
+		priv->locked_drive = NULL;
 	}
 }