We hold a reference count on the number of ports member in the
VLAN-aware bridge, as we only support one.

Instead of always incrementing / decrementing the reference count after
joining / leaving the bridge, simply do this accounting in the join /
leave functions.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>