genirq/cpuhotplug: Set force affinity flag on hotplug migration

Set the force migration flag when migrating interrupts away from an
outgoing CPU.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235445.681874648@linutronix.de

kernel/irq/cpuhotplug.c

@@ -79,7 +79,7 @@ static bool migrate_one_irq(struct irq_desc *desc)
 		brokeaff = true;
 	}
 
-	err = irq_do_set_affinity(d, affinity, false);
+	err = irq_do_set_affinity(d, affinity, true);
 	if (err) {
 		pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n",
 				    d->irq, err);