net: bridge: rename br_fdb_insert to br_fdb_add_local

br_fdb_insert() is a wrapper over fdb_insert() that also takes the
bridge hash_lock.

With fdb_insert() being renamed to fdb_add_local(), rename
br_fdb_insert() to br_fdb_add_local().

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>