This fixes a build failure in VTK when building against recent versions
of freetype.

  https://gitlab.kitware.com/vtk/vtk/-/merge_requests/7432

Patch by Ben Boeckel <ben.boeckel@kitware.com>

Subject: [PATCH] vtkFreeTypeTools: avoid using an internal macro

This macro has been removed upstream as it was always intended to be
private.
---
 Rendering/FreeType/vtkFreeTypeTools.cxx | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/Rendering/FreeType/vtkFreeTypeTools.cxx b/Rendering/FreeType/vtkFreeTypeTools.cxx
index c54289dc60..03b899c4da 100644
--- a/Rendering/FreeType/vtkFreeTypeTools.cxx
+++ b/Rendering/FreeType/vtkFreeTypeTools.cxx
@@ -378,8 +378,7 @@ FTC_CMapCache* vtkFreeTypeTools::GetCMapCache()
 }

 //----------------------------------------------------------------------------
-FT_CALLBACK_DEF(FT_Error)
-vtkFreeTypeToolsFaceRequester(
+static FT_Error vtkFreeTypeToolsFaceRequester(
   FTC_FaceID face_id, FT_Library lib, FT_Pointer request_data, FT_Face* face)
 {
 #if VTK_FTFC_DEBUG_CD
--
2.30.1