CLK: clk-twl6040: fix return value check in twl6040_clk_probe()

In case of error, the function clk_register() returns ERR_PTR()
and never returns NULL. The NULL test in the return value check
should be replaced with IS_ERR().

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

drivers/clk/clk-twl6040.c

@@ -92,8 +92,8 @@ static int __devinit twl6040_clk_probe(struct platform_device *pdev)
 
 	clkdata->mcpdm_fclk.init = &wm831x_clkout_init;
 	clkdata->clk = clk_register(&pdev->dev, &clkdata->mcpdm_fclk);
-	if (!clkdata->clk)
-		return -EINVAL;
+	if (IS_ERR(clkdata->clk))
+		return PTR_ERR(clkdata->clk);
 
 	dev_set_drvdata(&pdev->dev, clkdata);