rtc: mcp795: use rtc_lock/rtc_unlock

Avoid accessing directly rtc->ops_lock and use the RTC core helpers.

Signed-off-by: Alexandre Belloni <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/rtc/rtc-mcp795.c

···
 {
 	struct spi_device *spi = data;
 	struct rtc_device *rtc = spi_get_drvdata(spi);
-	struct mutex *lock = &rtc->ops_lock;
 	int ret;
 
-	mutex_lock(lock);
+	rtc_lock(rtc);
 
 	/* Disable alarm.
 	 * There is no need to clear ALM0IF (Alarm 0 Interrupt Flag) bit,
···
 			"Failed to disable alarm in IRQ (ret=%d)\n", ret);
 	rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
 
-	mutex_unlock(lock);
+	rtc_unlock(rtc);
 
 	return IRQ_HANDLED;
 }