igc: Clean up code

Address few community comments.
Remove unused code, will be added per demand.
Remove blank lines and unneeded includes.

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