net: hns3: Fix for warning uninitialized symbol hw_err_lst3

This patch fixes the smatch warning,

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:700
hclge_log_and_clear_ppp_error() error: uninitialized symbol
'hw_err_lst3'

Link: https://lkml.org/lkml/2018/10/23/430

Fixes: da2d072 ("net: hns3: Add enable and process hw errors from PPP")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -859,10 +859,12 @@ static int hclge_log_and_clear_ppp_error(struct hclge_dev *hdev, u32 cmd,
 		reset_level = HNAE3_FUNC_RESET;
 	}
 
-	err_sts = (le32_to_cpu(desc[0].data[4]) >> 8) & 0x3;
-	if (err_sts) {
-		hclge_log_error(dev, hw_err_lst3, err_sts);
-		reset_level = HNAE3_FUNC_RESET;
+	if (cmd == HCLGE_PPP_CMD0_INT_CMD) {
+		err_sts = (le32_to_cpu(desc[0].data[4]) >> 8) & 0x3;
+		if (err_sts) {
+			hclge_log_error(dev, hw_err_lst3, err_sts);
+			reset_level = HNAE3_FUNC_RESET;
+		}
 	}
 
 	/* clear PPP INT */