Mike Fleetwood authored Nov 04, 2019 and Curtis Gedak committed Nov 09, 2019

Upstream NILFS project calls the package nilfs-utils [1][2].  Arch Linux
/ CentOS / Fedora / OpenSUSE use the upstream name.  However Debian /
Ubuntu name it nilfs-tools [3] instead.

Document the needed software as:

    nilfs-utils / nilfs-tools

Upstream name first separated by slash from alternative names
distributions use.

[1] NILFS Download page
    https://nilfs.sourceforge.io/en/download.html
[2] NILFS Public Git Repositories
    https://nilfs.sourceforge.io/en/git_repos.html
[3] Debian package: nilfs-tools
    https://packages.debian.org/sid/nilfs-tools