vbo: remove a funky recursive call in glBegin

Reviewed-by: Mathias Fröhlich <mathias.froehlich@web.de>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3766>

src/mesa/vbo/vbo_exec_api.c

@@ -760,13 +760,9 @@ vbo_exec_Begin(GLenum mode)
       return;
    }
 
-   if (ctx->NewState) {
+   if (ctx->NewState)
       _mesa_update_state(ctx);
 
-      CALL_Begin(ctx->Exec, (mode));
-      return;
-   }
-
    if (!_mesa_valid_to_render(ctx, "glBegin")) {
       return;
    }