rtc: st-lpc: Simplify clk handling in st_rtc_probe()

Use devm_clk_get_enabled() instead of hand writing it. This simplifies
error handling and removes some lines of code.

Also use dev_err_probe() which filters -EPROBE_DEFER.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/992dd8c31be0bb5b8a9d8b5e8e94807ab0848a66.1686251455.git.christophe.jaillet@wanadoo.frSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-st-lpc.c

@@ -228,17 +228,13 @@ static int st_rtc_probe(struct platform_device *pdev)
 	enable_irq_wake(rtc->irq);
 	disable_irq(rtc->irq);
 
-	rtc->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(rtc->clk)) {
-		dev_err(&pdev->dev, "Unable to request clock\n");
-		return PTR_ERR(rtc->clk);
-	}
-
-	clk_prepare_enable(rtc->clk);
+	rtc->clk = devm_clk_get_enabled(&pdev->dev, NULL);
+	if (IS_ERR(rtc->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(rtc->clk),
+				     "Unable to request clock\n");
 
 	rtc->clkrate = clk_get_rate(rtc->clk);
 	if (!rtc->clkrate) {
-		clk_disable_unprepare(rtc->clk);
 		dev_err(&pdev->dev, "Unable to fetch clock rate\n");
 		return -EINVAL;
 	}
@@ -252,10 +248,8 @@ static int st_rtc_probe(struct platform_device *pdev)
 	do_div(rtc->rtc_dev->range_max, rtc->clkrate);
 
 	ret = devm_rtc_register_device(rtc->rtc_dev);
-	if (ret) {
-		clk_disable_unprepare(rtc->clk);
+	if (ret)
 		return ret;
-	}
 
 	return 0;
 }