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 <tanxiaofei@huawei.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/1612355981-6764-4-git-send-email-tanxiaofei@huawei.com

drivers/rtc/rtc-r7301.c

@@ -320,11 +320,10 @@ static irqreturn_t rtc7301_irq_handler(int irq, void *dev_id)
 {
 	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);
 
@@ -335,7 +334,7 @@ static irqreturn_t rtc7301_irq_handler(int irq, void *dev_id)
 		rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
 	}
 
-	spin_unlock_irqrestore(&priv->lock, flags);
+	spin_unlock(&priv->lock);
 
 	return ret;
 }