If someone uses the old vlan API to configure tunnel mappings we'll only
generate the old-style full port notification. That would be a problem
if we are monitoring the new vlan notifications for changes. The patch
resolves the issue by adding vlan notifications to the old tunnel netlink
code. As usual we try to compress the notifications for as many vlans
in a range as possible, thus a vlan tunnel change is considered able
to enter the "current" vlan notification range if:
 1. vlan exists
 2. it has actually changed (curr_change == true)
 3. it passes all standard vlan notification range checks done by
    br_vlan_can_enter_range() such as option equality, id continuity etc

Note that vlan tunnel changes (add/del) are considered a part of vlan
options so only RTM_NEWVLAN notification is generated with the relevant
information inside.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>