Fixed pass by value std::string.

radixio/hcdump.cc

@@ -350,7 +350,7 @@ void HCDump::reload()
     radix_line("Total mass: " << total);
 }
 
-HCDump::HCDump(const std::string path)
+HCDump::HCDump(const std::string& path)
     : mPath(path)
 {
     reload();

radixio/hcdump.hh

@@ -89,7 +89,7 @@ private:
 
 public:
 
-    HCDump(const std::string path);
+    HCDump(const std::string& path);
     void reload();
     std::string id() const;
     void setId(const std::string &id);