fix error

Author: yingcong-wu

libcxx/test/support/filesystem_test_helper.h

@@ -321,27 +321,27 @@ struct scoped_test_env
   // allow tests to call this unguarded.
 #if !defined(__FreeBSD__) && !defined(__APPLE__) && !defined(_WIN32)
     std::string create_socket(std::string file) {
-        file = sanitize_path(std::move(file));
+        std::string socket_file = sanitize_path(file);
 
         ::sockaddr_un address;
         address.sun_family = AF_UNIX;
 
         // If file.size() is too big, try to create a file directly inside
         // /tmp to make sure file path is short enough.
-        if (file.size() <= sizeof(address.sun_path) && utils::exists("/tmp")) {
+        if (socket_file.size() <= sizeof(address.sun_path) && utils::exists("/tmp")) {
           fs::path const tmp = "/tmp";
           std::size_t i      = std::hash<std::string>()(std::to_string(std::time(nullptr)));
           fs::path p         = tmp / ("libcxx-socket-" + file + "-" + std::to_string(i));
           while (utils::exists(p.string())) {
             p = tmp / ("libcxx-socket-" + file + "-" + std::to_string(++i));
           }
-          file = p.string();
+          socket_file = p.string();
         }
-        assert(file.size() <= sizeof(address.sun_path));
-        ::strncpy(address.sun_path, file.c_str(), sizeof(address.sun_path));
+        assert(socket_file.size() <= sizeof(address.sun_path));
+        ::strncpy(address.sun_path, socket_file.c_str(), sizeof(address.sun_path));
         int fd = ::socket(AF_UNIX, SOCK_STREAM, 0);
         assert(::bind(fd, reinterpret_cast<::sockaddr*>(&address), sizeof(address)) == 0);
-        return file;
+        return socket_file;
     }
 #endif