i40e: update error message when trying to add invalid filters

Re-word the error message displayed when adding a filter with an
invalid flow type. Additionally, report a distinct error message when
the IPv4 protocol is at fault.

Change-ID: Iba3d85b87f8d383c97c8bdd180df34a6adf3ee67
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>