backlight: backlight: Slighly simplify devm_of_find_backlight()

Use devm_add_action_or_reset() instead of devm_add_action()+hand writing
what is done in the release function, should an error occur.

This is more straightforward and saves a few lines of code.

While at it, remove a useless test in devm_backlight_release(). 'data' is
known to be not NULL when this function is called.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/f998a4291d865273afa0d1f85764a9ac7fbc1b64.1644738084.git.christophe.jaillet@wanadoo.fr

drivers/video/backlight/backlight.c

@@ -710,8 +710,7 @@ static void devm_backlight_release(void *data)
 {
 	struct backlight_device *bd = data;
 
-	if (bd)
-		put_device(&bd->dev);
+	put_device(&bd->dev);
 }
 
 /**
@@ -737,11 +736,10 @@ struct backlight_device *devm_of_find_backlight(struct device *dev)
 	bd = of_find_backlight(dev);
 	if (IS_ERR_OR_NULL(bd))
 		return bd;
-	ret = devm_add_action(dev, devm_backlight_release, bd);
-	if (ret) {
-		put_device(&bd->dev);
+	ret = devm_add_action_or_reset(dev, devm_backlight_release, bd);
+	if (ret)
 		return ERR_PTR(ret);
-	}
+
 	return bd;
 }
 EXPORT_SYMBOL(devm_of_find_backlight);