leds: turris-omnia: Use sysfs_emit() instead of sprintf()

Use the dedicated sysfs_emit() function instead of sprintf() in sysfs
attribute accessor brightness_show().
Signed-off-by: Marek Behún <kabel@kernel.org>
Link: https://lore.kernel.org/r/20230802160748.11208-4-kabel@kernel.orgSigned-off-by: Lee Jones <lee@kernel.org>

drivers/leds/leds-turris-omnia.c

@@ -166,7 +166,7 @@ static ssize_t brightness_show(struct device *dev, struct device_attribute *a,
 	if (ret < 0)
 		return ret;
 
-	return sprintf(buf, "%d\n", ret);
+	return sysfs_emit(buf, "%d\n", ret);
 }
 
 static ssize_t brightness_store(struct device *dev, struct device_attribute *a,