rvlan: default to "godown" at init time, not just "down"

This renumbers FSM states so the default is "godown", that forces "auth_vlan"
on down ports. Otherwise, at boot time they remain in their previous
status (for my own wrs this was vlan 0).

Before:

   wrs# /tmp2/rvlan-status
   wri2 (001bc5090845 <-> ): state down, vlan 0, pid 0, fd -1
   [...]

After:

   wrs# /etc/init.d/radiusvlan.sh stop
   wrs# /etc/init.d/radiusvlan.sh start
   wrs# /tmp2/rvlan-status
   wri2 (001bc5090845 <-> ): state down, vlan 4090, pid 0, fd -1
   [...]
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>