Driver: Vmxnet3: set CHECKSUM_UNNECESSARY for IPv6 packets

Driver: Vmxnet3: set CHECKSUM_UNNECESSARY for IPv6 packets

For IPv6, if the device indicates that the checksum is correct, set
CHECKSUM_UNNECESSARY.

Reported-by: Subbarao Narahari <snarahari@vmware.com>
Signed-off-by: Shrikrishna Khare <skhare@vmware.com>
Signed-off-by: Jin Heo <heoj@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Orabug: 23472394
(cherry picked from commit f0d437809d23999cb25207cfbe80c61e5703fdc1)
Signed-off-by: Dan Duval <dan.duval@oracle.com>
Conflict:

	drivers/net/vmxnet3/vmxnet3_int.h