[gtk+] Fix compilation warning: Use const gchar* variable

[Javier Jardón <jjardon src gnome org>]

commit d8f5ce4b545250a5c8dd50f21d031999b348a8e3
Author: Javier Jardón <jjardon gnome org>
Date:   Mon Nov 9 02:01:56 2009 +0100

    Fix compilation warning: Use const gchar* variable

 demos/gtk-demo/printing.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/demos/gtk-demo/printing.c b/demos/gtk-demo/printing.c
index 124eed9..34212d3 100644
--- a/demos/gtk-demo/printing.c
+++ b/demos/gtk-demo/printing.c
@@ -149,7 +149,8 @@ do_printing (GtkWidget *do_widget)
   GtkPrintOperation *operation;
   GtkPrintSettings *settings;
   PrintData *data;
-  gchar *uri, *dir, *ext;
+  gchar *uri, *ext;
+  const gchar *dir;
   GError *error = NULL;
 
   operation = gtk_print_operation_new ();