Making some cell locators more efficient.

Skipping an unneeded calculation for finding the closest point
since the result isn't being used.
Also fixed the name of the file in vtkCellTreeLocator.*.

Change-Id: Ia0f0ea70a0ab852d74c1dd116db4f374f021aead
Merge topic '14887_celllocator_efficiency' into master

d21be2bd Making some cell locators more efficient.