bridge: Fix flushing of dynamic FDB entries

The following commands should result in all the dynamic FDB entries
being flushed, but instead all the non-local (non-permanent) entries are
flushed:

 # bridge fdb add 00:aa:bb:cc:dd:ee dev dummy1 master static
 # bridge fdb add 00:11:22:33:44:55 dev dummy1 master dynamic
 # ip link set dev br0 type bridge fdb_flush
 # bridge fdb show brport dummy1
 00:00:00:00:00:01 master br0 permanent
 33:33:00:00:00:01 self permanent
 01:00:5e:00:00:01 self permanent

This is because br_fdb_flush() works with FDB flags and not the
corresponding enumerator values. Fix by passing the FDB flag instead.

After the fix:

 # bridge fdb add 00:aa:bb:cc:dd:ee dev dummy1 master static
 # bridge fdb add 00:11:22:33:44:55 dev dummy1 master dynamic
 # ip link set dev br0 type bridge fdb_flush
 # bridge fdb show brport dummy1
 00:aa:bb:cc:dd:ee master br0 static
 00:00:00:00:00:01 master br0 permanent
 33:33:00:00:00:01 self permanent
 01:00:5e:00:00:01 self permanent

Fixes: 1f78ee14

 ("net: bridge: fdb: add support for fine-grained flushing")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20221101185753.2120691-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>