The `BKE_animdata_driver_path_hack()` function has had almost no effect
since rB51b796ff1528, and basically boils down to:
```
return base_path ? base_path : RNA_path_from_ID_to_property(ptr, prop);
```
Since `base_path` was `NULL` in the majority of cases, it's just been
replaced by a direct call to `RNA_path_from_ID_to_property()`. The
conditional now just appears in one remaining case.
This relates to T91387.
Reviewed By: mont29
Differential Revision: https://developer.blender.org/D13646