Move source address lookup from fib6_rule_action to a helper. It will be
used in a later patch by a second variant for fib6_rule_action.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>