Add test to make sure that the localbypass option is on by default.

Add test to change vxlan localbypass to nolocalbypass and check
that packets are delivered to userspace.
Signed-off-by: Vladimir Nikishkin <vladimir@nikishkin.pw>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>