[gnome-builder/gnome-builder-3-28] buffer-manager: fix potential NULL dereference

[Christian Hergert <chergert src gnome org>]

commit f7935016c0d6a9b89dcb5e24d4256234a3696c03
Author: Christian Hergert <chergert redhat com>
Date:   Tue Mar 20 21:38:35 2018 -0700

    buffer-manager: fix potential NULL dereference
    
    As part of the fix in c954dea92d31b1ad7e2cdaa2c7a4ca9af34ec2d8
    we introduced this issue.

 src/libide/buffers/ide-buffer-manager.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/libide/buffers/ide-buffer-manager.c b/src/libide/buffers/ide-buffer-manager.c
index 56aa21421..da6aa8931 100644
--- a/src/libide/buffers/ide-buffer-manager.c
+++ b/src/libide/buffers/ide-buffer-manager.c
@@ -1273,7 +1273,7 @@ ide_buffer_manager_save_file_async (IdeBufferManager     *self,
                                 g_object_ref (task));
 
 unmodified:
-  unregister_auto_save (self, state->buffer);
+  unregister_auto_save (self, buffer);
 
   IDE_EXIT;
 }