Fix bus coords again

LocalFeeder/FeederSimulator.py

@@ -318,7 +318,7 @@ def get_bus_coords(self) -> Dict[str, Tuple[float, float]] | None:
         bus_path = os.path.join(os.path.dirname(self._feeder_file), "Buscoords.dss")
         if not os.path.exists(bus_path):
             self.bus_coords = None
-            return bus_coords
+            return self.bus_coords
         with open(bus_path, "r") as f:
             bus_coord_csv = csv.reader(f, delimiter=" ")
             bus_coords = {}