net/sched: cls_flower: Remove an unused field from the filter key structure

Commit c3f83241 "net: Add full IPv6 addresses to flow_keys" added an
unused instance of struct flow_dissector_key_addrs into struct fl_flow_key,
remove it.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reported-by: Hadar Hen Zion <hadarh@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>