Fix the semantic search example mistakes (#3363)

w5688414 · ZeyuChen · web-flow · commit 0711a60584dc · 2022-09-24T22:07:50.000+08:00
Co-authored-by: Zeyu Chen &lt;chenzeyu01@baidu.com&gt;
diff --git a/pipelines/examples/semantic-search/semantic_search_example.py b/pipelines/examples/semantic-search/semantic_search_example.py
@@ -114,7 +114,7 @@ def get_faiss_retriever(use_gpu):
 
         # save index
         document_store.save(args.index_name)
-    return document_store
+    return retriever
 
 
 def get_milvus_retriever(use_gpu):
