igc: Remove TCP segmentation TX fail counter

TCP segmentation TX context fail counter is not
applicable for i225 devices.
This patch comes to clean up this counter.

Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Aaron <Brown&lt;aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>