net: hns3: fix null pointer dereference before null check

pointer ndev is being dereferenced with the call to netif_running
before it is being null checked.  Re-order the code to only dereference
ndev after it has been null checked.

Detected by CoverityScan, CID#1457206 ("Dereference before null check")

Fixes: 9df8f79a4d ("net: hns3: Add DCB support when interacting with network stack")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.c

@@ -2865,7 +2865,7 @@ static int hns3_client_setup_tc(struct hnae3_handle *handle, u8 tc)
 {
 	struct hnae3_knic_private_info *kinfo = &handle->kinfo;
 	struct net_device *ndev = kinfo->netdev;
-	bool if_running = netif_running(ndev);
+	bool if_running;
 	int ret;
 	u8 i;
 
@@ -2875,6 +2875,8 @@ static int hns3_client_setup_tc(struct hnae3_handle *handle, u8 tc)
 	if (!ndev)
 		return -ENODEV;
 
+	if_running = netif_running(ndev);
+
 	ret = netdev_set_num_tc(ndev, tc);
 	if (ret)
 		return ret;