mmc: sdhci-s3c: fix NULL ptr access in sdhci_s3c_remove

If not all clocks have been defined in platform data, the driver will
cause a null pointer dereference when it is removed. This patch fixes
this issue.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/sdhci-s3c.c

@@ -483,9 +483,11 @@ static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
 	sdhci_remove_host(host, 1);
 
 	for (ptr = 0; ptr < 3; ptr++) {
+		if (sc->clk_bus[ptr]) {
 			clk_disable(sc->clk_bus[ptr]);
 			clk_put(sc->clk_bus[ptr]);
 		}
+	}
 	clk_disable(sc->clk_io);
 	clk_put(sc->clk_io);