openvswitch: disable LRO

Currently, openvswitch tries to disable LRO from the user space. This does
not work correctly when the device added is a vlan interface, though.
Instead of dealing with possibly complex stacked cross name space relations
in the user space, do the same as bridging does and call dev_disable_lro in
the kernel.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Flavio Leitner <fbl@redhat.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>