rtc: s35390a: drop needless struct s35390a::rtc member

The memory pointed to by the ::rtc member is managed via devres, and
no code in this driver uses it past _probe().

We can drop it from the structure and just use a local temporary
variable, reducing runtime memory consumption by a few bytes.

Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/20250304-rtc-cleanups-v2-12-d4689a71668c@linaro.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: andred

drivers/rtc/rtc-s35390a.c

@@ -63,7 +63,6 @@ MODULE_DEVICE_TABLE(of, s35390a_of_match);
 
 struct s35390a {
 	struct i2c_client *client[8];
-	struct rtc_device *rtc;
 	int twentyfourhour;
 };
 
@@ -422,6 +421,7 @@ static int s35390a_probe(struct i2c_client *client)
 	int err, err_read;
 	unsigned int i;
 	struct s35390a *s35390a;
+	struct rtc_device *rtc;
 	char buf, status1;
 	struct device *dev = &client->dev;
 
@@ -447,9 +447,9 @@ static int s35390a_probe(struct i2c_client *client)
 		}
 	}
 
-	s35390a->rtc = devm_rtc_allocate_device(dev);
-	if (IS_ERR(s35390a->rtc))
-		return PTR_ERR(s35390a->rtc);
+	rtc = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
 
 	err_read = s35390a_read_status(s35390a, &status1);
 	if (err_read < 0) {
@@ -480,17 +480,17 @@ static int s35390a_probe(struct i2c_client *client)
 
 	device_set_wakeup_capable(dev, 1);
 
-	s35390a->rtc->ops = &s35390a_rtc_ops;
-	s35390a->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
-	s35390a->rtc->range_max = RTC_TIMESTAMP_END_2099;
+	rtc->ops = &s35390a_rtc_ops;
+	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rtc->range_max = RTC_TIMESTAMP_END_2099;
 
-	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, s35390a->rtc->features);
-	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, s35390a->rtc->features );
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
 
 	if (status1 & S35390A_FLAG_INT2)
-		rtc_update_irq(s35390a->rtc, 1, RTC_AF);
+		rtc_update_irq(rtc, 1, RTC_AF);
 
-	return devm_rtc_register_device(s35390a->rtc);
+	return devm_rtc_register_device(rtc);
 }
 
 static struct i2c_driver s35390a_driver = {