rtc: use dev_warn()/dev_dbg()/pr_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/class.c

@@ -11,6 +11,8 @@
  * published by the Free Software Foundation.
 */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/module.h>
 #include <linux/rtc.h>
 #include <linux/kdev_t.h>
@@ -261,7 +263,7 @@ static int __init rtc_init(void)
 {
 	rtc_class = class_create(THIS_MODULE, "rtc");
 	if (IS_ERR(rtc_class)) {
-		printk(KERN_ERR "%s: couldn't create class\n", __FILE__);
+		pr_err("couldn't create class\n");
 		return PTR_ERR(rtc_class);
 	}
 	rtc_class->suspend = rtc_suspend;

drivers/rtc/rtc-dev.c

@@ -11,6 +11,8 @@
  * published by the Free Software Foundation.
 */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/module.h>
 #include <linux/rtc.h>
 #include <linux/sched.h>
@@ -462,7 +464,7 @@ void rtc_dev_prepare(struct rtc_device *rtc)
 		return;
 
 	if (rtc->id >= RTC_DEV_MAX) {
-		pr_debug("%s: too many RTC devices\n", rtc->name);
+		dev_dbg(&rtc->dev, "%s: too many RTC devices\n", rtc->name);
 		return;
 	}
 
@@ -480,10 +482,10 @@ void rtc_dev_prepare(struct rtc_device *rtc)
 void rtc_dev_add_device(struct rtc_device *rtc)
 {
 	if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1))
-		printk(KERN_WARNING "%s: failed to add char device %d:%d\n",
+		dev_warn(&rtc->dev, "%s: failed to add char device %d:%d\n",
 			rtc->name, MAJOR(rtc_devt), rtc->id);
 	else
-		pr_debug("%s: dev (%d:%d)\n", rtc->name,
+		dev_dbg(&rtc->dev, "%s: dev (%d:%d)\n", rtc->name,
 			MAJOR(rtc_devt), rtc->id);
 }
 
@@ -499,8 +501,7 @@ void __init rtc_dev_init(void)
 
 	err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
 	if (err < 0)
-		printk(KERN_ERR "%s: failed to allocate char dev region\n",
-			__FILE__);
+		pr_err("failed to allocate char dev region\n");
 }
 
 void __exit rtc_dev_exit(void)