use of uninitialized value in mv88e6185_port_link_state

Hi,

mv88e6185_port_link_state starts by inspecting state->interface. AFAICT,
it can be called from two places:

mv88e6xxx_link_state <-
dsa_slave_phylink_mac_link_state <-
phylink_get_mac_state

which does initialize state->interface before passing it, but also from
mv88e6xxx_port_setup_mac, which passes an uninitialized stack variable.
This seems like a bug, but I don't know what the proper fix would be.
Simply initialize state.interface to mode?

Rasmus