vmxnet3: fix cksum offload issues for non-udp tunnels

Commit dacce2be ("vmxnet3: add geneve and vxlan tunnel offload
support") added support for encapsulation offload. However, the inner
offload capability is to be restrictued to UDP tunnels.

This patch fixes the issue for non-udp tunnels by adding features
check capability and filtering appropriate features for non-udp tunnels.

Fixes: dacce2be

 ("vmxnet3: add geneve and vxlan tunnel offload support")
Signed-off-by: Ronak Doshi <doshir@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>