LMS-2844 bug fixed: Thumbnails had still sample link

SVN: 24776

screening/source/java/ch/systemsx/cisd/openbis/dss/etl/dto/api/impl/ImageContainerDataSet.java

@@ -98,9 +98,9 @@ public class ImageContainerDataSet extends DataSet<DataSetInformation> implement
         for (IDataSet thumbnailDataset : thumbnailDatasets)
         {
             thumbnailDataset.setSample(sampleOrNull);
-            if (thumbnailDatasets instanceof DataSet)
+            if (thumbnailDataset instanceof DataSet)
             {
-                ((DataSet<?>) thumbnailDatasets).getRegistrationDetails().getDataSetInformation()
+                ((DataSet<?>) thumbnailDataset).getRegistrationDetails().getDataSetInformation()
                         .setLinkSample(establishSampleLinkForContainedDataSets);
             }
         }