The --help text currently uses the "--umount" spelling, hence to the
same in the man page too.
And let's settle on "umount" instead of "unmount" here, since most folks
probably expect that when typing in a command, as util-linux' tool is
called "umount" after all, and so is the symlink "systemd-umount" we
install.
<varlistentry>
<term><option>-u</option></term>
- <term><option>--unmount</option></term>
+ <term><option>--umount</option></term>
<listitem><para>Stop the mount and automount units corresponding to the specified mount points
<replaceable>WHERE</replaceable>.</para>