net: allwinner: remove redundant irqsave and irqrestore in hardIRQ

The comment "holders of db->lock must always block IRQs" and related
code to do irqsave and irqrestore don't make sense since we are in a
IRQ-disabled hardIRQ context.

Cc: Maxime Ripard <mripard@kernel.org>
Cc: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/allwinner/sun4i-emac.c

@@ -640,13 +640,11 @@ static irqreturn_t emac_interrupt(int irq, void *dev_id)
 	struct net_device *dev = dev_id;
 	struct emac_board_info *db = netdev_priv(dev);
 	int int_status;
-	unsigned long flags;
 	unsigned int reg_val;
 
 	/* A real interrupt coming */
 
-	/* holders of db->lock must always block IRQs */
-	spin_lock_irqsave(&db->lock, flags);
+	spin_lock(&db->lock);
 
 	/* Disable all interrupts */
 	writel(0, db->membase + EMAC_INT_CTL_REG);
@@ -680,7 +678,7 @@ static irqreturn_t emac_interrupt(int irq, void *dev_id)
 		reg_val |= (0xf << 0) | (0x01 << 8);
 		writel(reg_val, db->membase + EMAC_INT_CTL_REG);
 	}
-	spin_unlock_irqrestore(&db->lock, flags);
+	spin_unlock(&db->lock);
 
 	return IRQ_HANDLED;
 }