Merge branch 'net-bridge-add-support-for-host-l2-mdb-entries'

Joachim Wiberg says:

====================
net: bridge: add support for host l2 mdb entries

Fix to an obvious omissions for layer-2 host mdb entries, this v2 adds
the missing selftest and some minor style fixes.

Note: this patch revealed some worrying problems in how the bridge
      forwards unknown BUM traffic and also how unknown multicast is
      forwarded when a IP multicast router is known, which a another
      (RFC) patch series intend to address.  That series will build
      on this selftest, hence the name of the test.

v2:
  - Add braces to other if/else clauses (Jakub)
  - Add selftest to verify add/del of mac/ipv4/ipv6 mdb entries (Jakub)
====================

Link: https://lore.kernel.org/r/20220411084054.298807-1-troglobit@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>