metag/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>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: James Hogan <james.hogan@imgtec.com>

arch/metag/kernel/irq.c

@@ -270,23 +270,25 @@ void migrate_irqs(void)
 
 	for_each_active_irq(i) {
 		struct irq_data *data = irq_get_irq_data(i);
+		struct cpumask *mask;
 		unsigned int newcpu;
 
 		if (irqd_is_per_cpu(data))
 			continue;
 
-		if (!cpumask_test_cpu(cpu, data->affinity))
+		mask = irq_data_get_affinity_mask(data);
+		if (!cpumask_test_cpu(cpu, mask))
 			continue;
 
-		newcpu = cpumask_any_and(data->affinity, cpu_online_mask);
+		newcpu = cpumask_any_and(mask, cpu_online_mask);
 
 		if (newcpu >= nr_cpu_ids) {
 			pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n",
 					    i, cpu);
 
-			cpumask_setall(data->affinity);
+			cpumask_setall(mask);
 		}
-		irq_set_affinity(i, data->affinity);
+		irq_set_affinity(i, mask);
 	}
 }
 #endif /* CONFIG_HOTPLUG_CPU */