rtc: mxc_v2: Add missing clk_disable_unprepare()

The call to clk_disable_unprepare() is left out in the error handling of
devm_rtc_allocate_device. Add it back.

Fixes: 5490a1e0 ("rtc: mxc_v2: fix possible race condition")
Signed-off-by: GUO Zihua <guozihua@huawei.com>
Link: https://lore.kernel.org/r/20221122085046.21689-1-guozihua@huawei.comSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-mxc_v2.c

@@ -336,8 +336,10 @@ static int mxc_rtc_probe(struct platform_device *pdev)
 	}
 
 	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
-	if (IS_ERR(pdata->rtc))
+	if (IS_ERR(pdata->rtc)) {
+		clk_disable_unprepare(pdata->clk);
 		return PTR_ERR(pdata->rtc);
+	}
 
 	pdata->rtc->ops = &mxc_rtc_ops;
 	pdata->rtc->range_max = U32_MAX;