[gtk+] Add a missing static

[Matthias Clasen <matthiasc src gnome org>]

commit f2569ba92b2d0505bdc341b5939fbe2a72baef50
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Nov 19 18:08:18 2011 -0500

    Add a missing static

 gtk/a11y/gtktreeviewaccessible.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gtk/a11y/gtktreeviewaccessible.c b/gtk/a11y/gtktreeviewaccessible.c
index 9d6132c..d6abe30 100644
--- a/gtk/a11y/gtktreeviewaccessible.c
+++ b/gtk/a11y/gtktreeviewaccessible.c
@@ -3089,7 +3089,7 @@ _gtk_tree_view_accessible_remove (GtkTreeView *treeview,
 
 /* NB: id is not checked, only columns < id are.
  * This is important so the function works for notification of removal of a column */
-guint
+static guint
 to_visible_column_id (GtkTreeView *treeview,
                       guint        id)
 {