net: hns3: fix for dereferencing before null checking

The netdev is dereferenced before null checking in the function
hns3_setup_tc.

This patch moves the dereferencing after the null checking.

Fixes: 76ad4f0e ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC")
Signed-off-by: NYunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: NPeng Li <lipeng321@huawei.com>
Signed-off-by: NHuazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hns3_enet.c

@@ -1510,12 +1510,12 @@ static void hns3_nic_get_stats64(struct net_device *netdev,
 static int hns3_setup_tc(struct net_device *netdev, void *type_data)
 {
 	struct tc_mqprio_qopt_offload *mqprio_qopt = type_data;
-	struct hnae3_handle *h = hns3_get_handle(netdev);
-	struct hnae3_knic_private_info *kinfo = &h->kinfo;
 	u8 *prio_tc = mqprio_qopt->qopt.prio_tc_map;
+	struct hnae3_knic_private_info *kinfo;
 	u8 tc = mqprio_qopt->qopt.num_tc;
 	u16 mode = mqprio_qopt->mode;
 	u8 hw = mqprio_qopt->qopt.hw;
+	struct hnae3_handle *h;
 
 	if (!((hw == TC_MQPRIO_HW_OFFLOAD_TCS &&
 	       mode == TC_MQPRIO_MODE_CHANNEL) || (!hw && tc == 0)))
@@ -1527,6 +1527,9 @@ static int hns3_setup_tc(struct net_device *netdev, void *type_data)
 	if (!netdev)
 		return -EINVAL;
 
+	h = hns3_get_handle(netdev);
+	kinfo = &h->kinfo;
+
 	return (kinfo->dcb_ops && kinfo->dcb_ops->setup_tc) ?
 		kinfo->dcb_ops->setup_tc(h, tc, prio_tc) : -EOPNOTSUPP;
 }