netstat: fix a segfault with --libxo

Fix a segfault when printing the "protocol" field. The field-format and
encoding-format were expecting different numbers of arguments.

Also, fix the width of the tcp-state field in encoded output.

PR: 292228
Fixes: c2b08c13c20 netstat: add support for UDP-Lite endpoints
MFC after: 1 week
Sponsored by: ConnectWise
Reviewed by: tuexen, js, des
Differential Revision: https://reviews.freebsd.org/D54567