COMP: Simplify code, and remove compiler warning

By using templated function instead of templated struct
with a single static member function, the code
was simplified and the compiler warning was removed.

ITK-4.5/itkTransformIOBase.hxx(57): warning #177: function "itk::<unnamed>::TypeName<double>::Get" was declared but never referenced
    static const char* Get()
                       ^
ITK-4.5/itkTransformIOBase.hxx(48): warning #177: function "itk::<unnamed>::TypeName<float>::Get" was declared but never referenced
    static const char* Get()

ITK-4.5/itkTransformFileWriter.hxx(167): warning #177: function "itk::<unnamed>::SetInputTransformWithOutputPrecisionType<double, double>::AddToTransformList" was declared but never referenced
    static void AddToTransformList(const TransformBaseTemplate<double> *transform, ConstTransformListType& transformList)
                ^

Change-Id: I1c98ba4cf9f86729010748f76f8f99395a8fc248
Merge topic 'RemoveICCCompWarnings'

96f043f COMP: Simplify code, and remove compiler warning