return hnsw name (#2501)

Signed-off-by: Ngroot <yihua.mo@zilliz.com>

core/src/db/Utils.cpp

@@ -301,14 +301,14 @@ GetIndexName(int32_t index_type) {
         {(int32_t)engine::EngineType::FAISS_IVFFLAT, "IVFFLAT"},
         {(int32_t)engine::EngineType::FAISS_IVFSQ8, "IVFSQ8"},
         {(int32_t)engine::EngineType::NSG_MIX, "NSG"},
-        {(int32_t)engine::EngineType::ANNOY, "ANNOY"},
         {(int32_t)engine::EngineType::FAISS_IVFSQ8H, "IVFSQ8H"},
         {(int32_t)engine::EngineType::FAISS_PQ, "PQ"},
         {(int32_t)engine::EngineType::SPTAG_KDT, "KDT"},
         {(int32_t)engine::EngineType::SPTAG_BKT, "BKT"},
         {(int32_t)engine::EngineType::FAISS_BIN_IDMAP, "IDMAP"},
         {(int32_t)engine::EngineType::FAISS_BIN_IVFFLAT, "IVFFLAT"},
-    };
+        {(int32_t)engine::EngineType::HNSW, "HNSW"},
+        {(int32_t)engine::EngineType::ANNOY, "ANNOY"}};
 
     if (index_type_name.find(index_type) == index_type_name.end()) {
         return "Unknow";