ixgbe: Cleanup incorrect header comments

The recent n-tuple patches added some comments to the headers
of the Flow Director functions that aren't accurate.  This
cleans them up, and is a purely cosmetic patch.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>