backlight: apple_bl: use pr_debug()/pr_err() instead of printk()

Use pr_debug()/pr_err() instead of printk() to allow dynamic debugging.
The pr_fmt prefix for pr_ macros is used.  Also fix checkpatch warnings as
below:

WARNING: Prefer pr_debug(... to printk(KERN_DEBUG, ...
WARNING: Prefer pr_err(... to printk(KERN_ERR, ...

[akpm@linux-foundation.org: use KBUILD_MODNAME, per Joe]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/apple_bl.c

@@ -16,6 +16,8 @@
  *  get at the firmware code in order to figure out what it's actually doing.
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
@@ -40,8 +42,6 @@ struct hw_data {
 
 static const struct hw_data *hw_data;
 
-#define DRIVER "apple_backlight: "
-
 /* Module parameters. */
 static int debug;
 module_param_named(debug, debug, int, 0644);
@@ -61,8 +61,7 @@ static int intel_chipset_send_intensity(struct backlight_device *bd)
 	int intensity = bd->props.brightness;
 
 	if (debug)
-		printk(KERN_DEBUG DRIVER "setting brightness to %d\n",
-		       intensity);
+		pr_debug("setting brightness to %d\n", intensity);
 
 	intel_chipset_set_brightness(intensity);
 	return 0;
@@ -77,8 +76,7 @@ static int intel_chipset_get_intensity(struct backlight_device *bd)
 	intensity = inb(0xb3) >> 4;
 
 	if (debug)
-		printk(KERN_DEBUG DRIVER "read brightness of %d\n",
-		       intensity);
+		pr_debug("read brightness of %d\n", intensity);
 
 	return intensity;
 }
@@ -108,8 +106,7 @@ static int nvidia_chipset_send_intensity(struct backlight_device *bd)
 	int intensity = bd->props.brightness;
 
 	if (debug)
-		printk(KERN_DEBUG DRIVER "setting brightness to %d\n",
-		       intensity);
+		pr_debug("setting brightness to %d\n", intensity);
 
 	nvidia_chipset_set_brightness(intensity);
 	return 0;
@@ -124,8 +121,7 @@ static int nvidia_chipset_get_intensity(struct backlight_device *bd)
 	intensity = inb(0x52f) >> 4;
 
 	if (debug)
-		printk(KERN_DEBUG DRIVER "read brightness of %d\n",
-		       intensity);
+		pr_debug("read brightness of %d\n", intensity);
 
 	return intensity;
 }
@@ -150,7 +146,7 @@ static int __devinit apple_bl_add(struct acpi_device *dev)
 	host = pci_get_bus_and_slot(0, 0);
 
 	if (!host) {
-		printk(KERN_ERR DRIVER "unable to find PCI host\n");
+		pr_err("unable to find PCI host\n");
 		return -ENODEV;
 	}
 
@@ -162,7 +158,7 @@ static int __devinit apple_bl_add(struct acpi_device *dev)
 	pci_dev_put(host);
 
 	if (!hw_data) {
-		printk(KERN_ERR DRIVER "unknown hardware\n");
+		pr_err("unknown hardware\n");
 		return -ENODEV;
 	}