cpuidle/powernv: avoid double irq enable coming out of idle

Since e1689795 ("cpuidle: Add common time keeping and irq enabling"),
cpuidle drivers are expected to return from ->enter with irqs disabled.

Update the cpuidle-powernv snooze loop to disable irqs before returning.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

drivers/cpuidle/cpuidle-powernv.c

@@ -76,6 +76,8 @@ static int snooze_loop(struct cpuidle_device *dev,
 	ppc64_runlatch_on();
 	clear_thread_flag(TIF_POLLING_NRFLAG);
 
+	local_irq_disable();
+
 	return index;
 }