ARM: cleanup: clk_get_sys() error handling

Fix clk_get_sys() error handling; IS_ERR() should be used rather than
IS_ERR_OR_NULL() to check for errors.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-tegra/tegra2_emc.c

@@ -276,7 +276,7 @@ static struct tegra_emc_pdata *tegra_emc_fill_pdata(struct platform_device *pdev
 	int i;
 
 	WARN_ON(pdev->dev.platform_data);
-	BUG_ON(IS_ERR_OR_NULL(c));
+	BUG_ON(IS_ERR(c));
 
 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 	pdata->tables = devm_kzalloc(&pdev->dev, sizeof(*pdata->tables),