fix:miss wait thread tasks finish in diskann. (#380)

Signed-off-by: cqy123456 <[email protected]>

thirdparty/DiskANN/src/partition_and_pq.cpp

@@ -532,6 +532,7 @@ int generate_pq_data_from_pivots(const std::string data_file,
  }
  }));
  }
+ knowhere::WaitAllSuccess(futures);
 
  futures.clear();
  futures.reserve(num_pq_chunks);