s3c2410fb: don't treat NULL clk as an error

clk_get() returns a struct clk cookie to the driver and some platforms
may return NULL if they only support a single clock.  clk_get() has only
failed if it returns a ERR_PTR() encoded pointer.

Cc: Vincent Sanders <support@simtec.co.uk>
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/video/s3c2410fb.c

@@ -13,6 +13,7 @@
 
 #include <linux/module.h>
 #include <linux/kernel.h>
+#include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/string.h>
 #include <linux/mm.h>
@@ -918,9 +919,9 @@ static int __devinit s3c24xxfb_probe(struct platform_device *pdev,
 	}
 
 	info->clk = clk_get(NULL, "lcd");
-	if (!info->clk || IS_ERR(info->clk)) {
+	if (IS_ERR(info->clk)) {
 		printk(KERN_ERR "failed to get lcd clock source\n");
-		ret = -ENOENT;
+		ret = PTR_ERR(info->clk);
 		goto release_irq;
 	}