tcpstates LPORT not working in 4.19 kernel

```
TIME,TIME(s),SKADDR,C-PID,C-COMM,IP,LADDR,LPORT,RADDR,RPORT,OLDSTATE,NEWSTATE,MS
14:03:49,0.000000,ffff8c7798a43b80,2081,sshd,4,172.31.18.109,0,20127,ESTABLISHED,FIN_WAIT1,0.000
```
**environment**
```
ubuntu@ip-172-31-18-109:/usr/share/bcc/tools$ uname -sr
Linux 4.19.0-041900-generic
```

```
ubuntu@ip-172-31-18-109:/usr/share/bcc/tools$ apt-cache policy bcc-tools
bcc-tools:
Installed: 0.10.0-1
Candidate: 0.10.0-1
Version table:
*** 0.10.0-1 500
500 https://repo.iovisor.org/apt/bionic bionic/main amd64 Packages
100 /var/lib/dpkg/status
```

Start with the tcpstates tool and reproduce the reported output on the stated Ubuntu 4.19.0-041900-generic environment, checking why LPORT is not reported correctly. Trace the tool's handling of local ports and verify that its output is correct on that kernel version.

Written by the indexing model from the issue text.