i40e/i40evf: add handling of writeback descriptor

If the writeback descriptor buffer was previously created, this gives it
to the AQ command request to be used to save the results.

Change-ID: I8c8a1af81e6ebed6d0a15ed31697fe1a6c4e3708
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_type.h b/drivers/net/ethernet/intel/i40evf/i40e_type.h
index 24a2693..cf865cc 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_type.h
+++ b/drivers/net/ethernet/intel/i40evf/i40e_type.h
@@ -486,6 +486,7 @@
 
 	/* state of nvm update process */
 	enum i40e_nvmupd_state nvmupd_state;
+	struct i40e_aq_desc nvm_wb_desc;
 
 	/* HMC info */
 	struct i40e_hmc_info hmc; /* HMC info struct */