[PATCH] rtc: stm32: fix clock leak on pinctrl probe failure

[Cong Nguyen <congnt264@gmail.com>]

stm32_rtc_probe() enables rtc_ck/pclk early and unwinds them through
the err: label on every later failure -- except a failing
devm_pinctrl_register_and_init() or pinctrl_enable(), which both
return directly, leaking both clocks. -EPROBE_DEFER is a routine
outcome from pinctrl lookups during boot, so each deferred retry
leaks another reference.

Route both through the existing err: label, matching every other
post-enable failure path in this function.

Fixes: 16ad2bc09efb ("rtc: stm32: add pinctrl and pinmux interfaces")
Assisted-by: Claude:claude-opus-4
Signed-off-by: Cong Nguyen <congnt264@gmail.com>
---
 drivers/rtc/rtc-stm32.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/rtc-stm32.c b/drivers/rtc/rtc-stm32.c
index d4ebf3eb54aa..e7a942f6c190 100644
--- a/drivers/rtc/rtc-stm32.c
+++ b/drivers/rtc/rtc-stm32.c
@@ -1175,12 +1175,16 @@ static int stm32_rtc_probe(struct platform_device *pdev)
 	stm32_rtc_clean_outs(rtc);
 
 	ret = devm_pinctrl_register_and_init(&pdev->dev, &stm32_rtc_pdesc, rtc, &pctl);
-	if (ret)
-		return dev_err_probe(&pdev->dev, ret, "pinctrl register failed");
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret, "pinctrl register failed");
+		goto err;
+	}
 
 	ret = pinctrl_enable(pctl);
-	if (ret)
-		return dev_err_probe(&pdev->dev, ret, "pinctrl enable failed");
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret, "pinctrl enable failed");
+		goto err;
+	}
 
 	/*
 	 * If INITS flag is reset (calendar year field set to 0x00), calendar
-- 
2.25.1