COMP: Logically dead code

CID 1080846 The indicated dead code may have performed some action;
that action will never occur.

In itk::​LaplacianRecursiveGaussianImageFilter<itk::​Image<float, 2u>,
itk::​Image<float,
2u>>::​itk::​LaplacianRecursiveGaussianImageFilter(): Code can never
be reached because of a logical contradiction

Change-Id: I4c2c10f0ac8d6f6e4c907c1efc6945e4ab6caf4b
Merge topic 'Coverity_itkLaplacianRecursiveGaussianImageFilter'

540d149 COMP: Logically dead code