If another actor in the scene enabled GL_TEXTURE_2D and the
vtkPolyDataMapper2D's input had a texture coordinate attribute, the
vtkPolyDataMapper2D would apply the texture map while mapping the
input. Fix by disabling GL_TEXTURE_2D if ScalarVisbility is off.

Change-Id: I187cafe3bebe03082be04e0f65b140f3f6b3ad67