Fix bug in graph_datahandling: HOST_TO_DEVICE and DEVICE_TO_HOST was swapped

src/pystencils_autodiff/graph_datahandling.py

@@ -179,14 +179,14 @@ class GraphDataHandling(pystencils.datahandling.SerialDataHandling):
 
     def to_cpu(self, name):
         super().to_cpu(name)
-        self.call_queue.append(DataTransfer(self._fields[name], DataTransferKind.HOST_TO_DEVICE))
+        self.call_queue.append(DataTransfer(self._fields[name], DataTransferKind.DEVICE_TO_HOST))
 
     def to_gpu(self, name):
         super().to_gpu(name)
         if name in self._custom_data_transfer_functions:
             self.call_queue.append('Custom Tranfer Function')
         else:
-            self.call_queue.append(DataTransfer(self._fields[name], DataTransferKind.DEVICE_TO_HOST))
+            self.call_queue.append(DataTransfer(self._fields[name], DataTransferKind.HOST_TO_DEVICE))
 
     def synchronization_function(self, names, stencil=None, target=None, **_):
         for name in names: