We need a GSO type for IPsec ESP to be able to integrate the IPsec hardware offloading infrastructure. Unfortunately, all gso_type flags are currently in use. This change extends gso_type from 'unsigned short' to 'unsigned int'.
Changes from v1: - Place the remaining two byte hole in front, suggested by Eric Dumazet. - Skipping the memset of the two byte hole is unnecessary as it does not matter if we memset two or four bytes more, suggested by Alexander Duyck.
