ethernet: 3c509: Update documentation to match MAINTAINERS

There has been apparently a single message only ever publicly posted by
David Ruggiero, back in 2002, which added this documentation piece among
others, and MAINTAINERS was never updated accordingly.  It is therefore
doubtful that his maintainer status has actually come into effect.  Just
replace the reference then so as not to confuse people.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Link: https://patch.msgid.link/alpine.DEB.2.21.2605201207380.1450@angie.orcam.me.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/networking/device_drivers/ethernet/3com/3c509.rst

@@ -12,7 +12,7 @@ release 1.0
 28 February 2002
 
 Current maintainer (corrections to):
-  David Ruggiero <jdr@farfalle.com>
+  Maciej W. Rozycki <macro@orcam.me.uk>
 
 Introduction
 ============