net: vxlan: lwt: Fix vxlan local traffic.

vxlan driver has bypass for local vxlan traffic, but that
depends on information about all VNIs on local system in
vxlan driver. This is not available in case of LWT.
Therefore following patch disable encap bypass for LWT
vxlan traffic.

Fixes: ee122c79

 ("vxlan: Flow based tunneling").
Reported-by: Jakub Libosvar <jlibosva@redhat.com>
Signed-off-by: Pravin B Shelar <pshelar@ovn.org>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>