ia64/irq: Use access helper irq_data_get_affinity_mask()

This is a preparatory patch for moving irq_data struct members.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/20150713131034.630273860@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/ia64/kernel/iosapic.c

@@ -838,7 +838,7 @@ iosapic_unregister_intr (unsigned int gsi)
 	if (iosapic_intr_info[irq].count == 0) {
 #ifdef CONFIG_SMP
 		/* Clear affinity */
-		cpumask_setall(irq_get_irq_data(irq)->affinity);
+		cpumask_setall(irq_get_affinity_mask(irq));
 #endif
 		/* Clear the interrupt information */
 		iosapic_intr_info[irq].dest = 0;