Fix typo in Xen patch from 2.6.35.5

--- linux-2.6.35.noarch.orig/drivers/xen/events.c
+++ linux-2.6.35.noarch/drivers/xen/events.c
@@ -935,7 +935,7 @@ static struct irq_chip xen_dynamic_chip 
 	.retrigger	= retrigger_dynirq,
 };
 
-static struct irq_chip en_percpu_chip __read_mostly = {
+static struct irq_chip xen_percpu_chip __read_mostly = {
 	.name		= "xen-percpu",
 
 	.disable	= disable_dynirq,