net: hns3: add protection when get SFP speed as 0

In some case, the MAC speed get from hardware maybe 0, it should
not be set to mac->speed.
Signed-off-by: Guojia Liao <liaoguojia@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

@@ -2835,6 +2835,12 @@ static int hclge_get_sfp_info(struct hclge_dev *hdev, struct hclge_mac *mac)
 		return ret;
 	}
 
+	/* In some case, mac speed get from IMP may be 0, it shouldn't be
+	 * set to mac->speed.
+	 */
+	if (!le32_to_cpu(resp->speed))
+		return 0;
+
 	mac->speed = le32_to_cpu(resp->speed);
 	/* if resp->speed_ability is 0, it means it's an old version
 	 * firmware, do not update these params