sparseirq: fix desc->lock init

Impact: cleanup

init_one_irq_desc() does not initialize the desc->lock properly -
you cannot init a lock by memcpying some other lock on it.

This happens to work right now (because irq_desc_init is never in use),
but it's a dangerous construct nevertheless, so fix it.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kernel/irq/handle.c

@@ -93,6 +93,8 @@ void __attribute__((weak)) arch_init_chip_data(struct irq_desc *desc, int cpu)
 static void init_one_irq_desc(int irq, struct irq_desc *desc, int cpu)
 {
 	memcpy(desc, &irq_desc_init, sizeof(struct irq_desc));
+
+	spin_lock_init(&desc->lock);
 	desc->irq = irq;
 #ifdef CONFIG_SMP
 	desc->cpu = cpu;

kernel/irq/numa_migrate.c

@@ -42,6 +42,7 @@ static void init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
 		 struct irq_desc *desc, int cpu)
 {
 	memcpy(desc, old_desc, sizeof(struct irq_desc));
+	spin_lock_init(&desc->lock);
 	desc->cpu = cpu;
 	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 	init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids);