xen/events: Don't check the info for NULL as it is already done.

The list operation checks whether the 'info' structure that is
retrieved from the list is NULL (otherwise it would not been able
to retrieve it). This check is not neccessary.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

drivers/xen/events.c

@@ -779,7 +779,7 @@ int xen_irq_from_pirq(unsigned pirq)
 	mutex_lock(&irq_mapping_update_lock);
 
 	list_for_each_entry(info, &xen_irq_list_head, list) {
-		if (info == NULL || info->type != IRQT_PIRQ)
+		if (info->type != IRQT_PIRQ)
 			continue;
 		irq = info->irq;
 		if (info->u.pirq.pirq == pirq)