The vmxnet3 driver enables vlan filters if filtering is enabled for
any vlan.  In promiscuous mode the filter table is cleared to in
order to disable filtering.  However, if a vlan device is subsequently
created that vlan will be added to the filter, re-engaging it.  As a
result, not only do we not see all the vlans in promiscuous mode, we
don't even see vlans for which a filter was previously created.

CC: Scott J. Goldman <scottjg@vmware.com>
CC: Shreyas Bhatewara <sbhatewara@vmware.com>
CC: VMware PV-Drivers <pv-drivers@vmware.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: Shreyas N Bhatewara <sbhatewara@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>