[libgit2-glib] ggit-object-factory.c: Fix return annotations

[Igor Gnatenko <ignatenko src gnome org>]

commit 0aa93854a1c551cad0196dcba2af933690cb6298
Author: Brian C. Lane <bcl redhat com>
Date:   Wed Aug 30 17:07:06 2017 -0700

    ggit-object-factory.c: Fix return annotations
    
    Add (nullable) as needed.

 libgit2-glib/ggit-object-factory.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/libgit2-glib/ggit-object-factory.c b/libgit2-glib/ggit-object-factory.c
index ac9fc53..59db627 100644
--- a/libgit2-glib/ggit-object-factory.c
+++ b/libgit2-glib/ggit-object-factory.c
@@ -215,7 +215,7 @@ convert_to_gparameter (GObjectConstructParam *params,
  *
  * Construct a new object.
  *
- * Returns: (transfer full): a #GObject.
+ * Returns: (transfer full) (nullable): a #GObject or %NULL.
  *
  **/
 GObject *