[PATCH] genirq: Fix irqs_unhandled in note_interrupt

[Angus Chen <angus.chen@jaguarmicro.com>]

Commit 4f27c00bf80f ("Improve behaviour of spurious IRQ detect")
introduced a age of last_unhandled,after irq_count reached 100000,
we set irqs_unhandled = 0,but we didn't clear last_unhandled.
So we can see the print of irq_spurious_proc_show is not consistent.
Like below:
root@jmkernel:~# cat /proc/irq/138/spurious
count 99998
unhandled 1
last_unhandled 1543930240 ms

root@jmkernel:~# cat /proc/irq/138/spurious
count 0
unhandled 0
last_unhandled 1548915240 ms

we can set last_unhandled=1 as a prompting message.

Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com>
---
 kernel/irq/spurious.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 02b2daf07441..e883df04bdf1 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -428,7 +428,7 @@ void note_interrupt(struct irq_desc *desc, irqreturn_t action_ret)
 		mod_timer(&poll_spurious_irq_timer,
 			  jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
 	}
-	desc->irqs_unhandled = 0;
+	desc->irqs_unhandled = 1;
 }
 
 bool noirqdebug __read_mostly;
-- 
2.34.1