BUG #14779. Fixes for vtkDistancePolyDataFilter.

Misc. fixes for vtkDistancePolyDataFilter.

Change-Id: I7265dc053e369130e695216ceba37a0fd9d7b27c
Merge topic '14779_cleanup_vtkDistancePolyDataFilter' into master

92be9c22 BUG #14779. Fixes for vtkDistancePolyDataFilter.