gtk3: fpicker, try removing both locations

Change-Id: I0f10d03c1e4481e8efa765e52b5264071c86a3cf
(cherry picked from commit ce07affe)

vcl/unx/gtk/fpicker/SalGtkFilePicker.cxx

@@ -418,30 +418,31 @@ shrinkFilterName( const OUString &rFilterName, bool bAllowNoStar = false )
     return aRealName;
 }
 
+static void
+dialog_remove_buttons(GtkWidget *pActionArea)
+{
+    GList *pChildren =
+        gtk_container_get_children( GTK_CONTAINER( pActionArea ) );
+
+    for( GList *p = pChildren; p; p = p->next )
+        gtk_widget_destroy( GTK_WIDGET( p->data ) );
+
+    g_list_free( pChildren );
+}
+
 static void
 dialog_remove_buttons( GtkDialog *pDialog )
 {
     g_return_if_fail( GTK_IS_DIALOG( pDialog ) );
 
-    GtkWidget *pActionArea;
-
 #if GTK_CHECK_VERSION(3,0,0)
 #if GTK_CHECK_VERSION(3,12,0)
-    pActionArea = gtk_dialog_get_header_bar(pDialog);
-#else
-    pActionArea = gtk_dialog_get_action_area(pDialog);
+    dialog_remove_buttons(gtk_dialog_get_header_bar(pDialog));
 #endif
+    dialog_remove_buttons(gtk_dialog_get_action_area(pDialog));
 #else
-    pActionArea = pDialog->action_area;
+    dialog_remove_buttons(pDialog->action_area);
 #endif
-
-    GList *pChildren =
-        gtk_container_get_children( GTK_CONTAINER( pActionArea ) );
-
-    for( GList *p = pChildren; p; p = p->next )
-        gtk_widget_destroy( GTK_WIDGET( p->data ) );
-
-    g_list_free( pChildren );
 }
 
 namespace {