rtc: m48t86: drop needless struct m48t86_rtc_info::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-m48t86.c

···
 struct m48t86_rtc_info {
 	void __iomem *index_reg;
 	void __iomem *data_reg;
-	struct rtc_device *rtc;
 };
 
 static unsigned char m48t86_readb(struct device *dev, unsigned long addr)
···
 static int m48t86_rtc_probe(struct platform_device *pdev)
 {
 	struct m48t86_rtc_info *info;
+	struct rtc_device *rtc;
 	unsigned char reg;
 	int err;
 	struct nvmem_config m48t86_nvmem_cfg = {
···
 		return -ENODEV;
 	}
 
-	info->rtc = devm_rtc_allocate_device(&pdev->dev);
-	if (IS_ERR(info->rtc))
-		return PTR_ERR(info->rtc);
+	rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
 
-	info->rtc->ops = &m48t86_rtc_ops;
+	rtc->ops = &m48t86_rtc_ops;
 
-	err = devm_rtc_register_device(info->rtc);
+	err = devm_rtc_register_device(rtc);
 	if (err)
 		return err;
 
-	devm_rtc_nvmem_register(info->rtc, &m48t86_nvmem_cfg);
+	devm_rtc_nvmem_register(rtc, &m48t86_nvmem_cfg);
 
 	/* read battery status */
 	reg = m48t86_readb(&pdev->dev, M48T86_D);