Code cleanup.
* jk/unused:
dir.c: drop unused "untracked" from treat_path_fast()
sequencer: handle ignore_footer when parsing trailers
test-advise: check argument count with argc instead of argv
sparse-checkout: fill in some options boilerplate
sequencer: drop repository argument from run_git_commit()
push: drop unused repo argument to do_push()
assert PARSE_OPT_NONEG in parse-options callbacks
env--helper: write to opt->value in parseopt helper
drop unused argc parameters
convert: drop unused crlf_action from check_global_conv_flags_eol()