[FIX] call this.print on end of ReceiptScreenWidget.show instead of explicit window.print

print method already existed, probably to allow overriding printing, but it was not actually called

bzr revid: xmo@openerp.com-20130704141256-u5n7a4kfmqac8n9z

addons/point_of_sale/static/src/js/screens.js

@@ -820,7 +820,7 @@ function openerp_pos_screens(instance, module){ //module is instance.point_of_sa
                     click: function() { self.finishOrder(); },
                 });
 
-            window.print();
+            this.print();
         },
         print: function() {
             window.print();