[pygobject] return NULL instead of -1 which fixes crash when introspection is turned off

[John Palmieri <johnp src gnome org>]

commit 97774cb149c5b03d5ef82a5af3f19e2ce4d79d0b
Author: John (J5) Palmieri <johnp redhat com>
Date:   Mon Oct 4 12:43:31 2010 -0400

    return NULL instead of -1 which fixes crash when introspection is turned off
    
    * see https://bugzilla.gnome.org/show_bug.cgi?id=631158

 gi/pygi.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gi/pygi.h b/gi/pygi.h
index 551bb6f..da71d28 100644
--- a/gi/pygi.h
+++ b/gi/pygi.h
@@ -155,7 +155,7 @@ static inline PyObject *
 pygi_get_property_value (PyGObject *instance,
                          const gchar *attr_name)
 {
-    return -1;
+    return NULL;
 }
 
 static inline gint