video: s3c-fb: fix possible division by zero in s3c_fb_calc_pixclk

Divider value can be zero and it makes division by zero
from debug message in s3c_fb_calc_pixclk; therefore, it
should be fixed.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

drivers/video/s3c-fb.c

@@ -361,7 +361,7 @@ static int s3c_fb_calc_pixclk(struct s3c_fb *sfb, unsigned int pixclk)
 	result = (unsigned int)tmp / 1000;
 
 	dev_dbg(sfb->dev, "pixclk=%u, clk=%lu, div=%d (%lu)\n",
-		pixclk, clk, result, clk / result);
+		pixclk, clk, result, result ? clk / result : clk);
 
 	return result;
 }