iavf: update comments and file checks to match iavf

Some small things were missed with recent name changes
from i40e to iavf.  Having a separate patch allows to
correct the small misses in one place.

Signed-off-by: Alice Michael <alice.michael@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>