[cogl] matrix: add missing transfer annotation

[Robert Bragg <rbragg src gnome org>]

commit 0eb6432dcc428b5d39cc22db9f1644d73f492401
Author: Lionel Landwerlin <llandwerlin gmail com>
Date:   Tue Sep 3 15:41:16 2013 +0100

    matrix: add missing transfer annotation
    
    Reviewed-by: Robert Bragg <robert linux intel com>
    
    (cherry picked from commit 28e37775c02a8518ebbaa4846a5aef3b82080dfb)

 cogl/cogl-matrix.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/cogl/cogl-matrix.h b/cogl/cogl-matrix.h
index 91d12a8..4ff2abc 100644
--- a/cogl/cogl-matrix.h
+++ b/cogl/cogl-matrix.h
@@ -518,8 +518,8 @@ cogl_matrix_equal (const void *v1, const void *v2);
  * Allocates a new #CoglMatrix on the heap and initializes it with
  * the same values as @matrix.
  *
- * Returns: A newly allocated #CoglMatrix which should be freed using
- * cogl_matrix_free()
+ * Return value: (transfer full): A newly allocated #CoglMatrix which
+ * should be freed using cogl_matrix_free()
  *
  * Since: 1.6
  */