writing out KnGLL and its components in sampleDict

[iainsymthe]

Cannot print out mfp, KnGLL_rho, KnGLL_T, KnGLL_U even when they are set to "on" in transport properties.
Running postProcess -func sampleDict with these variables in the fields entry gives the error
Executing functionObjects
--> FOAM Warning :
From function Foam::label Foam::sampledSets::classifyFields()
in file sampledSet/sampledSets/sampledSetsGrouping.C at line 80

Cannot find registered field matching

and the variable values are not printed out.