fontchooserwidget: Revise handling of named instances

Allowing to tweak the axes of named instances does
not do any harm. If we don't, we have to worry that
we need at least one non-named-instance in the face
list, and make it more obvious how to pick it out.

gtk/gtkfontchooserwidget.c

@@ -1522,13 +1522,6 @@ should_show_axis (hb_ot_var_axis_info_t *ax)
   return TRUE;
 }
 
-static gboolean
-is_named_instance (hb_font_t *font)
-{
-  /* FIXME */
-  return FALSE;
-}
-
 static struct {
   guint32 tag;
   const char *name;
@@ -1598,7 +1591,7 @@ add_axis (GtkFontChooserWidget  *fontchooser,
 
   adjustment_changed (axis->adjustment, axis);
   g_signal_connect (axis->adjustment, "value-changed", G_CALLBACK (adjustment_changed), axis);
-  if (is_named_instance (hb_font) || !should_show_axis (ax))
+  if (!should_show_axis (ax))
     {
       gtk_widget_hide (axis->label);
       gtk_widget_hide (axis->scale);