backlight: generic_bl: use pr_info() instead of printk()

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

WARNING: printk() should include KERN_ facility level

[akpm@linux-foundation.org: use KBUILD_MODNAME, per Joe]
Signed-off-by: Jingoo Han <jg1.han@samsung.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/generic_bl.c

@@ -9,6 +9,8 @@
  *
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
@@ -106,7 +108,7 @@ static int genericbl_probe(struct platform_device *pdev)
 
 	generic_backlight_device = bd;
 
-	printk("Generic Backlight Driver Initialized.\n");
+	pr_info("Generic Backlight Driver Initialized.\n");
 	return 0;
 }
 
@@ -120,7 +122,7 @@ static int genericbl_remove(struct platform_device *pdev)
 
 	backlight_device_unregister(bd);
 
-	printk("Generic Backlight Driver Unloaded\n");
+	pr_info("Generic Backlight Driver Unloaded\n");
 	return 0;
 }