docs: admin: devices: drop confusing outdated statement on Latex

The statement that the Latex version of Linux Device List is unmaintained,
must go back to some historic time where there were actually two separate
document sources, one in a txt format and another in a tex format (maybe
even just on lanana.org).

Nowadays, html and tex are generated from the ReST document file and the
statement might be confused, believing the actual generated LaTeX document
from the maintained ReST document could be an unmaintained one.

Remove this statement on the LaTeX version and only keep pointing out that
the version on lanana.org is no longer maintained.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20220704122537.3407-6-lukas.bulwahn@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>