net: igb calls skb_set_hash

Drivers should call skb_set_hash to set the hash and its type
in an skbuff.

Signed-off-by: Tom Herbert <therbert@google.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>