Reordering of internal temperature calculation to avoid FPEs. iDof was

defaulting to VSMALL (1e-300) for monoatomics but being multiplied by kb:
O(1e-23) for field calculation.

src/postProcessing/functionObjects/utilities/dsmcFields/dsmcFields.C

@@ -184,7 +184,7 @@ void Foam::dsmcFields::write()
                     obr_,
                     IOobject::NO_READ
                 ),
-                2.0/(dsmcCloud::kb*iDofMean)*internalEMean
+                (2.0/dsmcCloud::kb)*(internalEMean/iDofMean)
             );
 
             Info<< "    Calculating overallT field." << endl;