net: hns3: direct return when receive a unknown mailbox message

Currently, the driver didn't return when receive a unknown
mailbox message, and continue checking whether need to
generate a response. It's unnecessary and may be incorrect.

Fixes: bb5790b ("net: hns3: refactor mailbox response scheme between PF and VF")
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: IronShen

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

@@ -1077,12 +1077,13 @@ static void hclge_mbx_request_handling(struct hclge_mbx_ops_param *param)
 
 	hdev = param->vport->back;
 	cmd_func = hclge_mbx_ops_list[param->req->msg.code];
-	if (cmd_func)
-		ret = cmd_func(param);
-	else
+	if (!cmd_func) {
 		dev_err(&hdev->pdev->dev,
 			"un-supported mailbox message, code = %u\n",
 			param->req->msg.code);
+		return;
+	}
+	ret = cmd_func(param);
 
 	/* PF driver should not reply IMP */
 	if (hnae3_get_bit(param->req->mbx_need_resp, HCLGE_MBX_NEED_RESP_B) &&