net/vxlan: Share RX skb de-marking and checksum checks with ovs

net/vxlan: Share RX skb de-marking and checksum checks with ovs

[ Upstream commit d0bc65557ad09a57b4db176e9e3ccddb26971453 ]

Make sure the practice set by commit 0afb166 "vxlan: Add capability
of Rx checksum offload for inner packet" is applied when the skb
goes through the portion of the RX code which is shared between
vxlan netdevices and ovs vxlan port instances.

Cc: Joseph Gasparakis <joseph.gasparakis@intel.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>