sctp_test usage message is missing options -X and -w

[stepnem]

Likely candidates can also be found using something like the following script:

#!/bin/sh

set -e

oldpwd=$(pwd)
testdir=$(mktemp -d)
cd "$testdir"
trap 'cd "$oldpwd" && rm -rf "$testdir"' EXIT

curl -sL https://github.com/sctp/lksctp-tools/raw/master/src/apps/sctp_test.c |
  tee s_t.c |
  sed -ne '/void usage(/,/* usage() */ {s/\\[nt]//g;p}' >usage

options=$(sed -ne 's/^.*getopt([^"]*"\([^"]*\)").*$/\1/p' s_t.c).

while true; do
  option=$(printf %c "$options")
  case $option in
    :) ;;
    .) exit;;
    ?) grep -qE "(^|[^[:alnum:]_-])-$option($|[^[:alnum:]_-])" usage ||
      printf '%s\n' "$option";;
  esac
  options=${options#?}
done