ARM/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: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/arm/kernel/irq.c

@@ -140,7 +140,7 @@ int __init arch_probe_nr_irqs(void)
 static bool migrate_one_irq(struct irq_desc *desc)
 {
 	struct irq_data *d = irq_desc_get_irq_data(desc);
-	const struct cpumask *affinity = d->affinity;
+	const struct cpumask *affinity = irq_data_get_affinity_mask(d);
 	struct irq_chip *c;
 	bool ret = false;
 
@@ -160,7 +160,7 @@ static bool migrate_one_irq(struct irq_desc *desc)
 	if (!c->irq_set_affinity)
 		pr_debug("IRQ%u: unable to set affinity\n", d->irq);
 	else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret)
-		cpumask_copy(d->affinity, affinity);
+		cpumask_copy(irq_data_get_affinity_mask(d), affinity);
 
 	return ret;
 }