net: rbridge: cleaning old code used during development

this code was used during development when we were using rbridges as
bridges (without using VLANs) in order to connect the different nodes
between each other

Reported-by: François Cachereul <f.cachereul@alphalink.fr>
Signed-off-by: William Dauchy <william@gandi.net>
Signed-off-by: Ahmed Amamou <ahmed@gandi.net>