Currently ebrctl is network.filters, but the utility is
used by libvirt in nova compute, as part of a Mellanox vif driver.
The ubuntu packages install network.filters with the nova-network package.
But this vif driver only works with Neutron.
To help fix that, this patch move it to compute.filters to ensure it is
always installed with Nova.
Closes-Bug: #1453418
Change-Id: Ib61a565c10edfa662c15fac339b2cbd9bb673631