net/mlx5e: Don't sync netdev state when not registered

Skip setting netdev vxlan ports and netdev rx_mode on driver load
when netdev is not yet registered.

Synchronizing with netdev state is needed only on reset flow where the
netdev remains registered for the whole reset period.

This also fixes an access before initialization of net_device.addr_list_lock
- which for some reason initialized on register_netdev - where we queued
set_rx_mode work on driver load before netdev registration.

Fixes: 26e59d80 ("net/mlx5e: Implement mlx5e interface attach/detach callbacks")
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Mohamad Haj Yahia <mohamad@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>