netfilter: flowtable: fix missing FLOWI_FLAG_ANYSRC flag
The nf_flow_table gets route through ip_route_output_key. If the saddr
is not local one, then FLOWI_FLAG_ANYSRC flag should be set. Without
this flag, the route lookup for other_dst will fail.
Fixes: 3412e1641828 (netfilter: flowtable: nft_flow_route use more data for reverse route) Signed-off-by: wenxu <wenxu@chinatelecom.cn> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>