Fix CQS signal. Id] 88153895 -- readability-redundant-string-init in fbcode/faiss (#4283)

Summary: Pull Request resolved: https://github.com/facebookresearch/faiss/pull/4283

Reviewed By: dtolnay

Differential Revision: D72700675

fbshipit-source-id: 631daa12b11b45e16aa5877b6d6f5556753ce53f

tests/test_hamming.cpp

@@ -17,7 +17,7 @@ template <typename T>
 std::string print_data(
         std::shared_ptr<std::vector<T>> data,
         const size_t divider) {
-    std::string ret = "";
+    std::string ret;
     for (int i = 0; i < data->size(); ++i) {
         if (i % divider) {
             ret += " ";