bridge: update vlan dev link state for bridge netdev changes

If vlan bridge binding is enabled, then the link state of a vlan device
that is an upper device of the bridge tracks the state of bridge ports
that are members of that vlan. But this can only be done when the link
state of the bridge is up. If it is down, then the link state of the
vlan devices must also be down. This is to maintain existing behavior
for when STP is enabled and there are no live ports, in which case the
link state for the bridge and any vlan devices is down.

Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>