genirq: Introduce irq_do_set_affinity() to reduce duplicated code

All invocations of chip->irq_set_affinity() are doing the same return
value checks. Let them all use a common function.

[ tglx: removed the silly likely while at it ]

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Keping Chen <chenkeping@huawei.com>
Link: http://lkml.kernel.org/r/1333120296-13563-3-git-send-email-jiang.liu@huawei.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
index c3c8975..ca3f4aa 100644
--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -42,17 +42,8 @@
 	 * For correct operation this depends on the caller
 	 * masking the irqs.
 	 */
-	if (likely(cpumask_any_and(desc->pending_mask, cpu_online_mask)
-		   < nr_cpu_ids)) {
-		int ret = chip->irq_set_affinity(&desc->irq_data,
-						 desc->pending_mask, false);
-		switch (ret) {
-		case IRQ_SET_MASK_OK:
-			cpumask_copy(desc->irq_data.affinity, desc->pending_mask);
-		case IRQ_SET_MASK_OK_NOCOPY:
-			irq_set_thread_affinity(desc);
-		}
-	}
+	if (cpumask_any_and(desc->pending_mask, cpu_online_mask) < nr_cpu_ids)
+		irq_do_set_affinity(&desc->irq_data, desc->pending_mask, false);
 
 	cpumask_clear(desc->pending_mask);
 }