igbvf: Fix code comments and whitespace

Fix the code comments to align with the drivers/net/ commenting style.
Also fix other checkpatch errors such as using tabs where possible and
properly wrap lines to conform to the 80 char limit (unless it is
a string).

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