Cleanup: Remove scene frame macros (`CFRA` et al.)

Removes the following macros for scene/render frame values:
- `CFRA`
- `SUBFRA`
- `SFRA`
- `EFRA`

These macros don't add much, other than saving a few characters when typing.
It's not immediately clear what they refer to, they just hide what they
actually access. Just be explicit and clear about that.
Plus these macros gave read and write access to the variables, so eyesores like
this would be done (eyesore because it looks like assigning to a constant):
```
CFRA = some_frame_nbr;
```

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D15311

1 files changed, 2 insertions, 2 deletions

diff --git a/source/blender/io/gpencil/intern/gpencil_io_capi.cc b/source/blender/io/gpencil/intern/gpencil_io_capi.cc
index 84b273bc570..ac5f8cf7c8d 100644
--- a/source/blender/io/gpencil/intern/gpencil_io_capi.cc
+++ b/source/blender/io/gpencil/intern/gpencil_io_capi.cc
@@ -112,7 +112,7 @@ static bool gpencil_io_export_pdf(Depsgraph *depsgraph,
           continue;
         }
 
-        CFRA = i;
+        scene->r.cfra = i;
         BKE_scene_graph_update_for_newframe(depsgraph);
         exporter->prepare_camera_params(scene, iparams);
         exporter->frame_number_set(i);
@@ -122,7 +122,7 @@ static bool gpencil_io_export_pdf(Depsgraph *depsgraph,
       result = exporter->write();
       /* Back to original frame. */
       exporter->frame_number_set(iparams->frame_cur);
-      CFRA = iparams->frame_cur;
+      scene->r.cfra = iparams->frame_cur;
       BKE_scene_camera_switch_update(scene);
       BKE_scene_graph_update_for_newframe(depsgraph);
       break;