rtc: rtc-ds2404: use dev_err() instead of printk()

Fix the checkpatch warning as below:

  WARNING: Prefer netdev_err(netdev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-ds2404.c

@@ -70,7 +70,7 @@ static int ds2404_gpio_map(struct ds2404 *chip, struct platform_device *pdev,
 	for (i = 0; i < ARRAY_SIZE(ds2404_gpio); i++) {
 		err = gpio_request(ds2404_gpio[i].gpio, ds2404_gpio[i].name);
 		if (err) {
-			printk(KERN_ERR "error mapping gpio %s: %d\n",
+			dev_err(&pdev->dev, "error mapping gpio %s: %d\n",
 				ds2404_gpio[i].name, err);
 			goto err_request;
 		}
@@ -177,7 +177,7 @@ static void ds2404_write_memory(struct device *dev, u16 offset,
 
 	for (i = 0; i < length; i++) {
 		if (out[i] != ds2404_read_byte(dev)) {
-			printk(KERN_ERR "read invalid data\n");
+			dev_err(dev, "read invalid data\n");
 			return;
 		}
 	}