video: s3c-fb: use pr_debug instead of printk

This patch uses pr_debug instead of printk to allow dynamic debugging.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

drivers/video/s3c-fb.c

@@ -47,7 +47,7 @@
 #ifdef CONFIG_FB_S3C_DEBUG_REGWRITE
 #undef writel
 #define writel(v, r) do { \
-	printk(KERN_DEBUG "%s: %08x => %p\n", __func__, (unsigned int)v, r); \
+	pr_debug("%s: %08x => %p\n", __func__, (unsigned int)v, r); \
 	__raw_writel(v, r); \
 } while (0)
 #endif /* FB_S3C_DEBUG_REGWRITE */