foamToVTK writes to undecomposed case

Steps to reproduce

On any case:

decomposePar
cd processor0
foamToVTK

this will create ../VTK since it uses the globalPath but does not check for parallel running.

Possible fixes

    const fileName outputDir(runTime.globalPath()/vtkDirName);

should check for Pstream::parRun() and use runTime.path() if not parallel