i40e/i40evf: initialize context descriptor

Driver needs to initialize all members of context descriptor. Stale
data is possible otherwise.

Change-ID: Idc6b53af45583509da42d5ec0824cbaf78aee64f
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --cc drivers/net/ethernet/intel/i40e/i40e_txrx.c
Simple merge

diff --cc drivers/net/ethernet/intel/i40evf/i40e_txrx.c
Simple merge