[libgda] Use right macro, as those are void functions

[Vivien Malerba <vivien src gnome org>]

commit be22b029f43c55fbda84dc028e98aa78f7c86016
Author: Arthur Neves <arthurnn gmail com>
Date:   Tue Feb 9 18:09:32 2016 -0500

    Use right macro, as those are void functions
    
    We need to use g_return_if_fail so we wont return any value, as those
    two functions are void.
    
    I was getting an error when compiling the source, thats how I found those"

 control-center/gdaui-bar.c   |    4 ++--
 tools/browser/ui-customize.c |    2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/control-center/gdaui-bar.c b/control-center/gdaui-bar.c
index 71238fd..68b7f0c 100644
--- a/control-center/gdaui-bar.c
+++ b/control-center/gdaui-bar.c
@@ -496,8 +496,8 @@ gdaui_bar_add_search_entry (GdauiBar *bar)
 void
 gdaui_bar_add_widget (GdauiBar *bar, GtkWidget *widget)
 {
-       g_return_val_if_fail (GDAUI_IS_BAR (bar), NULL);
-       g_return_val_if_fail (GTK_IS_WIDGET (widget), NULL);
+       g_return_if_fail (GDAUI_IS_BAR (bar));
+       g_return_if_fail (GTK_IS_WIDGET (widget));
 
        gtk_box_pack_start (GTK_BOX (bar->priv->action_area), widget, FALSE, FALSE, 0);
 }
diff --git a/tools/browser/ui-customize.c b/tools/browser/ui-customize.c
index 70d4ee3..9602eb1 100644
--- a/tools/browser/ui-customize.c
+++ b/tools/browser/ui-customize.c
@@ -106,7 +106,7 @@ customization_data_get (GObject *object)
 void
 customization_data_init (GObject *object, GtkToolbar *toolbar, GtkHeaderBar *header)
 {
-       g_return_val_if_fail (G_IS_OBJECT (object), NULL);
+       g_return_if_fail (G_IS_OBJECT (object));
        if (customization_data_get (object)) {
                g_warning ("Customization for %p already exists", object);
                customization_data_release (object);