led: triggers: Fix dereferencing of null pointer

[ Upstream commit 4016ba85880b252365d11bc7dc899450f2c73ad7 ]

Error was detected by PVS-Studio:
V522 Dereferencing of the null pointer 'led_cdev->trigger' might take place.

Fixes: 2282e125a406 ("leds: triggers: let struct led_trigger::activate() return an error code")
Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index e4cb381..005b839 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -171,11 +171,11 @@
 		trig->deactivate(led_cdev);
 err_activate:
 
-	led_cdev->trigger = NULL;
-	led_cdev->trigger_data = NULL;
 	write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
 	list_del(&led_cdev->trig_list);
 	write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags);
+	led_cdev->trigger = NULL;
+	led_cdev->trigger_data = NULL;
 	led_set_brightness(led_cdev, LED_OFF);
 	kfree(event);