net: hns3: return 0 and print warning when hit duplicate MAC

When set 2 same MAC to different function of one port, IMP
will return error as the later one may modify the origin one.
This will cause bond fail for 2 VFs of one port.

Driver just print warning and return 0 with this patch, so
if set same MAC address, it will return 0 but do not really
configure HW.
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c

@@ -5962,8 +5962,11 @@ int hclge_add_uc_addr_common(struct hclge_vport *vport,
 	}
 
 	/* check if we just hit the duplicate */
-	if (!ret)
-		ret = -EINVAL;
+	if (!ret) {
+		dev_warn(&hdev->pdev->dev, "VF %d mac(%pM) exists\n",
+			 vport->vport_id, addr);
+		return 0;
+	}
 
 	dev_err(&hdev->pdev->dev,
 		"PF failed to add unicast entry(%pM) in the MAC table\n",