irq_work: Convert flags to atomic_t

We need to convert flags to atomic_t in order to later fix an ordering
issue on atomic_cmpxchg() failure. This will allow us to use atomic_fetch_or().

Also clarify the nature of those flags.

[ mingo: Converted two more usage site the original patch missed. ]

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191108160858.31665-2-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index ca65327..8657273 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2961,7 +2961,7 @@ static void wake_up_klogd_work_func(struct irq_work *irq_work)
 
 static DEFINE_PER_CPU(struct irq_work, wake_up_klogd_work) = {
 	.func = wake_up_klogd_work_func,
-	.flags = IRQ_WORK_LAZY,
+	.flags = ATOMIC_INIT(IRQ_WORK_LAZY),
 };
 
 void wake_up_klogd(void)