ipvlan: Add the skb->mark as flow4's member to lookup route

[ Upstream commit a98a4ebc8c61d20f0150d6be66e0e65223a347af ]

Current codes don't use skb->mark to assign flowi4_mark, it would
make the policy route rule with fwmark doesn't work as expected.

Signed-off-by: Gao Feng <gfree.wind@vip.163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>