networking: remove duplicate methods from networking_sitnl.c

networking: remove duplicate methods from networking_sitnl.c

The net_ctx_init/reset/free methods of sitnl are the same dummy
methods that are already defined for non-Linux platforms in the
networking.h header.

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20220402070902.30282-2-a@unstable.cc>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg24054.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>