[cogl] index-buffer: add missing transfer annotation

[Robert Bragg <rbragg src gnome org>]

commit 1cfc79e64200e1228588c25622f9aaeb43dae66b
Author: Lionel Landwerlin <llandwerlin gmail com>
Date:   Tue Sep 3 15:31:09 2013 +0100

    index-buffer: add missing transfer annotation
    
    Reviewed-by: Robert Bragg <robert linux intel com>
    
    (cherry picked from commit 59fa8b22bd6effd82cb837c597040b576b31b01c)

 cogl/cogl-index-buffer.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/cogl/cogl-index-buffer.h b/cogl/cogl-index-buffer.h
index 074452c..e9fdda9 100644
--- a/cogl/cogl-index-buffer.h
+++ b/cogl/cogl-index-buffer.h
@@ -57,6 +57,8 @@ typedef struct _CoglIndexBuffer             CoglIndexBuffer;
  * cogl_buffer_set_data() or by mapping it into the application's
  * address space using cogl_buffer_map().
  *
+ * Return value: (transfer full): A newly allocated #CoglIndexBuffer
+ *
  * Since: 1.4
  * Stability: Unstable
  */