r8152: allow userland to disable multicast

r8152: allow userland to disable multicast

The rtl8152 driver does not disable multicasting when userspace asks
it to. For example:
 $ ifconfig eth0 -multicast -allmulti
 $ tcpdump -p -i eth0  # will still capture multicast frames

Fix by clearing the device multicast filter table when multicast and
allmulti are both unset.

Tested as follows:
- Set multicast on eth0 network interface
- verify that multicast packets are coming in:
  $ tcpdump -p -i eth0
- Clear multicast and allmulti on eth0 network interface
- verify that no more multicast packets are coming in:
  $ tcpdump -p -i eth0

Signed-off-by: Sven van Ashbrook <svenva@chromium.org>
Acked-by: Hayes Wang <hayeswang@realtek.com>
Link: https://lore.kernel.org/r/20220830045923.net-next.v1.1.I4fee0ac057083d4f848caf0fa3a9fd466fc374a0@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>