x86: fix typo in irq_desc array

when SPARSE_IRQ is not used, should still use irq_desc->lock
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/irq/handle.c

@@ -253,7 +253,7 @@ struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 		.chip = &no_irq_chip,
 		.handle_irq = handle_bad_irq,
 		.depth = 1,
-		.lock = __SPIN_LOCK_UNLOCKED(sparse_irqs->lock),
+		.lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock),
 #ifdef CONFIG_SMP
 		.affinity = CPU_MASK_ALL
 #endif