In a28239f005 we made --files-from obey --no-traverse. In the
process this caused --files-from without --no-traverse to do a
complete recursive scan unecessarily.
This was only noticeable in users of fs/march, so sync/copy/move/etc
not in ls/lsf/etc.
This fix makes sure that we use conventional directory listings in
fs/march unless `--files-from` and `--no-traverse` is set or
`--fast-list` is active.
Fixes#3619