rtc: ep93xx: drop needless struct ep93xx_rtc::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 <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alexandre Belloni <[e-mail]>

drivers/rtc/rtc-ep93xx.c

···
 
 struct ep93xx_rtc {
 	void __iomem	*mmio_base;
-	struct rtc_device *rtc;
 };
 
 static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload,
···
 static int ep93xx_rtc_probe(struct platform_device *pdev)
 {
 	struct ep93xx_rtc *ep93xx_rtc;
+	struct rtc_device *rtc;
 	int err;
 
 	ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL);
···
 
 	platform_set_drvdata(pdev, ep93xx_rtc);
 
-	ep93xx_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
-	if (IS_ERR(ep93xx_rtc->rtc))
-		return PTR_ERR(ep93xx_rtc->rtc);
+	rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
 
-	ep93xx_rtc->rtc->ops = &ep93xx_rtc_ops;
-	ep93xx_rtc->rtc->range_max = U32_MAX;
+	rtc->ops = &ep93xx_rtc_ops;
+	rtc->range_max = U32_MAX;
 
-	err = rtc_add_group(ep93xx_rtc->rtc, &ep93xx_rtc_sysfs_files);
+	err = rtc_add_group(rtc, &ep93xx_rtc_sysfs_files);
 	if (err)
 		return err;
 
-	return devm_rtc_register_device(ep93xx_rtc->rtc);
+	return devm_rtc_register_device(rtc);
 }
 
 static const struct of_device_id ep93xx_rtc_of_ids[] = {