Fix command output

[deemp]

Details

Currently, eo-phi-normalizer outputs "ExitSuccess" at the end of the output of some commands. Examples:

$ eo-phi-normalizer --version
2.2.2
ExitSuccess

$ eo-phi-normalizer rewrite --help
Usage: eo-phi-normalizer rewrite [-r|--rules FILE] [-c|--chain] [-j|--json] 
                                 [--tex] [-o|--output-file FILE] [-s|--single] 
                                 [-l|--single-line] [--max-depth INT] 
                                 [--max-growth-factor INT] [FILE] 
                                 [-d|--dependency-file FILE]

  Rewrite a PHI program.

Available options:
  -r,--rules FILE          FILE with user-defined rules. If unspecified, builtin
                           set of rules is used.
  -c,--chain               Output rewriting steps.
  -j,--json                Output JSON.
  --tex                    Output LaTeX.
  -o,--output-file FILE    Output to FILE. When this option is not specified,
                           output to stdout.
  -s,--single              Output a single expression.
  -l,--single-line         Output a single expression on a single line. Has
                           effect only if the --single is enabled.
  --max-depth INT          Maximum depth of rules application. Defaults to 10.
  --max-growth-factor INT  The factor by which to allow the input term to grow
                           before stopping. Defaults to 10.
  FILE                     FILE to read input from. When no FILE is specified,
                           read from stdin.
  -d,--dependency-file FILE
                           FILE to read dependencies from (zero or more
                           dependency files allowed).
  -h,--help                Show this help text
ExitSuccess

The commands fail with the exit code 1.

However, the Markdown updates succeed.