rtc: r7301: Replace spin_lock_irqsave with spin_lock in hard IRQ

It is redundant to do irqsave and irqrestore in hardIRQ context, where
it has been in a irq-disabled context.

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

drivers/rtc/rtc-r7301.c

···
 {
 	struct rtc_device *rtc = dev_id;
 	struct rtc7301_priv *priv = dev_get_drvdata(rtc->dev.parent);
-	unsigned long flags;
 	irqreturn_t ret = IRQ_NONE;
 	u8 alrm_ctrl;
 
-	spin_lock_irqsave(&priv->lock, flags);
+	spin_lock(&priv->lock);
 
 	rtc7301_select_bank(priv, 1);
 
···
 		rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
 	}
 
-	spin_unlock_irqrestore(&priv->lock, flags);
+	spin_unlock(&priv->lock);
 
 	return ret;
 }