STYLE: Fix #ifndef used with itkTubeTK_fake_library_src.h
STYLE: Fix #ifndef used with itkTubeTK_fake_library_src.h

thewtex/TubeTK,KitwareMedical/TubeTK,aylward/ITKTubeTK,aylward/ITKTubeTK,KitwareMedical/ITKTubeTK,aylward/ITKTubeTK,thewtex/TubeTK,KitwareMedical/ITKTubeTK,KitwareMedical/ITKTubeTK,KitwareMedical/TubeTK,thewtex/TubeTK,KitwareMedical/TubeTK,KitwareMedical/ITKTubeTK,KitwareMedical/TubeTK,aylward/ITKTubeTK,thewtex/TubeTK