netfilter: bridge: re-order br_nf_pre_routing_finish_ipv6()

Put br_nf_pre_routing_finish_ipv6() after daddr_was_changed() and
br_nf_pre_routing_finish_bridge() to prepare calling these functions
from there.

Signed-off-by: Bernhard Thaler <bernhard.thaler@wvnet.at>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>