Fix OpenGL errors in vtkEDLShading.cxx

vtkEDLShading was binding textures before creating them. That was causing
segfaults after changes to VTK for more aggressive OpenGL checks. This fixes
that issue.

Change-Id: I699cc4f90356adab7cd384cc83892e78657c46e7
Merge topic 'update_vtk_master' into next

e502e1b Fix OpenGL errors in vtkEDLShading.cxx