[gnome-panel] button-widget.c: fix deprecated warnings

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 1f525aa17ac4f3fef9c5a8a03442c4ee3c6e2b09
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sun May 25 15:50:47 2014 +0300

    button-widget.c: fix deprecated warnings

 gnome-panel/button-widget.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/gnome-panel/button-widget.c b/gnome-panel/button-widget.c
index 6c87441..ade20cd 100644
--- a/gnome-panel/button-widget.c
+++ b/gnome-panel/button-widget.c
@@ -171,11 +171,11 @@ button_widget_reload_pixbuf (ButtonWidget *button)
                                         button->priv->orientation & PANEL_HORIZONTAL_MASK ? 
button->priv->size : -1,
                                         &error);
                if (error) {
-                       //FIXME: this is not rendered at button->priv->size
-                       button->priv->pixbuf =
-                               gtk_widget_render_icon_pixbuf (GTK_WIDGET (button),
-                                                               GTK_STOCK_MISSING_IMAGE,
-                                                               (GtkIconSize) -1);
+                       button->priv->pixbuf = gtk_icon_theme_load_icon (button->priv->icon_theme,
+                                                                        "image-missing",
+                                                                        button->priv->size,
+                                                                        0, NULL);
+
                        g_free (error);
                }