Fix bug with VAE slicing in autoencoder_dc.py (#12343)

Author: mingyi456

src/diffusers/models/autoencoders/autoencoder_dc.py

@@ -617,7 +617,7 @@ def decode(self, z: torch.Tensor, return_dict: bool = True) -> Union[DecoderOutp
                 returned.
         """
         if self.use_slicing and z.size(0) > 1:
-            decoded_slices = [self._decode(z_slice).sample for z_slice in z.split(1)]
+            decoded_slices = [self._decode(z_slice) for z_slice in z.split(1)]
             decoded = torch.cat(decoded_slices)
         else:
             decoded = self._decode(z)