functionObjects: Simplified the handling of the post-processing mode

Replaced the 'postProcess' argument to the 'write' and 'execute'
functions with the single static member 'postProcess' in the
functionObject base-class.

src/functionObjects/field/yPlus/yPlus.C

@@ -170,7 +170,7 @@ bool Foam::functionObjects::yPlus::read(const dictionary& dict)
 }
 
 
-bool Foam::functionObjects::yPlus::execute(const bool postProcess)
+bool Foam::functionObjects::yPlus::execute()
 {
     const fvMesh& mesh = refCast<const fvMesh>(obr_);
 
@@ -198,7 +198,7 @@ bool Foam::functionObjects::yPlus::execute(const bool postProcess)
 }
 
 
-bool Foam::functionObjects::yPlus::write(const bool postProcess)
+bool Foam::functionObjects::yPlus::write()
 {
     const volScalarField& yPlus =
         obr_.lookupObject<volScalarField>(type());