rtc; pcf2123: fix possible alarm race condition

Clear the flag after disabling the alarm to ensure the alarm doesn't fire
between clearing the flag and disabling the alarm.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20190819182656.29744-2-alexandre.belloni@bootlin.comSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-pcf2123.c

@@ -274,13 +274,13 @@ static int pcf2123_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 
 	dev_dbg(dev, "%s: alm is %ptR\n", __func__, &alm->time);
 
-	/* Ensure alarm flag is clear */
-	ret = regmap_update_bits(pdata->map, PCF2123_REG_CTRL2, CTRL2_AF, 0);
+	/* Disable alarm interrupt */
+	ret = regmap_update_bits(pdata->map, PCF2123_REG_CTRL2, CTRL2_AIE, 0);
 	if (ret)
 		return ret;
 
-	/* Disable alarm interrupt */
-	ret = regmap_update_bits(pdata->map, PCF2123_REG_CTRL2, CTRL2_AIE, 0);
+	/* Ensure alarm flag is clear */
+	ret = regmap_update_bits(pdata->map, PCF2123_REG_CTRL2, CTRL2_AF, 0);
 	if (ret)
 		return ret;