i40e/i40evf: Drop unused tx_ring argument

Some of the tx_ring arguments can be deleted since they are not used.

Change-ID: I99275b0f191d7f63ec2f05061919904940c36f31
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>