Fix T78225: Vertex Colors not showing in edit mode

This should be using the mesh_cd_ldata_get_from_mesh function in
order to get ldata from BMesh in edit mode.

Reviewed By: sergey

Maniphest Tasks: T78225

Differential Revision: https://developer.blender.org/D8818

source/blender/draw/intern/draw_cache_impl_mesh.c

@@ -169,7 +169,7 @@ static void mesh_cd_calc_active_vcol_layer(const Mesh *me, DRW_MeshCDMask *cd_us
 static void mesh_cd_calc_active_mloopcol_layer(const Mesh *me, DRW_MeshCDMask *cd_used)
 {
   const Mesh *me_final = editmesh_final_or_this(me);
-  const CustomData *cd_ldata = &me_final->ldata;
+  const CustomData *cd_ldata = mesh_cd_ldata_get_from_mesh(me_final);
 
   int layer = CustomData_get_active_layer(cd_ldata, CD_MLOOPCOL);
   if (layer != -1) {