batman-adv: change the MAC of each VLAN upon ndo_set_mac_address

The MAC address of the soft-interface is used to initialise
the "non-purge" TT entry of each existing VLAN. Therefore
when the user invokes ndo_set_mac_address() all the
"non-purge" TT entries have to be updated, not only the one
belonging to the non-tagged network.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>