net: hns: mdio->irq is an array, so no need to check if it is null

The null check on mdio->irq is redundant since mdio->irq is an array
of PHY_MAX_ADDR ints and hence can never be null. Remove the redundant
check.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c

@@ -684,8 +684,7 @@ hns_mac_register_phydev(struct mii_bus *mdio, struct hns_mac_cb *mac_cb,
 	if (!phy || IS_ERR(phy))
 		return -EIO;
 
-	if (mdio->irq)
-		phy->irq = mdio->irq[addr];
+	phy->irq = mdio->irq[addr];
 
 	/* All data is now stored in the phy struct;
 	 * register it