rtc: st-lpc: Use IRQF_NO_AUTOEN flag in request_irq()

If request_irq() fails in st_rtc_probe(), there is no need to enable
the irq, and if it succeeds, disable_irq() after request_irq() still has
a time gap in which interrupts can come.

request_irq() with IRQF_NO_AUTOEN flag will disable IRQ auto-enable when
request IRQ.

Fixes: b5b2bdfc2893 ("rtc: st: Add new driver for ST's LPC RTC")
Signed-off-by: Jinjie Ruan <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alexandre Belloni <[e-mail]>

drivers/rtc/rtc-st-lpc.c

···
 		return -EINVAL;
 	}
 
-	ret = devm_request_irq(&pdev->dev, rtc->irq, st_rtc_handler, 0,
-			       pdev->name, rtc);
+	ret = devm_request_irq(&pdev->dev, rtc->irq, st_rtc_handler,
+			       IRQF_NO_AUTOEN, pdev->name, rtc);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to request irq %i\n", rtc->irq);
 		return ret;
 	}
 
 	enable_irq_wake(rtc->irq);
-	disable_irq(rtc->irq);
 
 	rtc->clk = devm_clk_get_enabled(&pdev->dev, NULL);
 	if (IS_ERR(rtc->clk))