be2net: Fix incorrect setting of tunnel offload flag in netdev features

An earlier commit to resolve an issue with encapsulation offloads missed
setting a bit in the outer netdev features flag. This results in loss of TSO
feature on a VxLAN interface.

Fixes: 630f4b70

 ("Export tunnel offloads only when a VxLAN tunnel is created")

Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>