[gom] gom: Fix return value error in gom_sorting_add

[Ting-Wei Lan <lantw src gnome org>]

commit d9362b170ce6829e54a859d2bc8664b1b52ad30b
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Sat Aug 8 20:16:48 2015 +0800

    gom: Fix return value error in gom_sorting_add
    
    https://bugzilla.gnome.org/show_bug.cgi?id=753381

 gom/gom-sorting.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gom/gom-sorting.c b/gom/gom-sorting.c
index e1768e3..ee5ef2a 100644
--- a/gom/gom-sorting.c
+++ b/gom/gom-sorting.c
@@ -234,7 +234,7 @@ gom_sorting_add (GomSorting     *sorting,
    if (!pspec) {
       g_warning("No such property %s::%s",
                 g_type_name(resource_type), property_name);
-      return NULL;
+      return;
    }
 
    o->pspec = g_param_spec_ref(pspec);