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/gpencil_modifiers/intern/MOD_gpencilmirror.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilmirror.c
index df66251159c..1d62e930caa 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilmirror.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilmirror.c
@@ -163,7 +163,7 @@ static void bakeModifier(Main *UNUSED(bmain),
   LISTBASE_FOREACH (bGPDlayer *, gpl, &gpd->layers) {
     LISTBASE_FOREACH (bGPDframe *, gpf, &gpl->frames) {
       /* apply mirror effects on this frame */
-      CFRA = gpf->framenum;
+      scene->r.cfra = gpf->framenum;
       BKE_scene_graph_update_for_newframe(depsgraph);
 
       /* compute mirror effects on this frame */
@@ -172,7 +172,7 @@ static void bakeModifier(Main *UNUSED(bmain),
   }
 
   /* return frame state and DB to original state */
-  CFRA = oldframe;
+  scene->r.cfra = oldframe;
   BKE_scene_graph_update_for_newframe(depsgraph);
 }