Fru:Change of pass by value to const reference

Change-Id: Idf53d897375f895fc52ec0a49ee0a2517ed32258
Signed-off-by: Pavithra Barithaya <pbaritha@in.ibm.com>
diff --git a/libpldmresponder/fru.hpp b/libpldmresponder/fru.hpp
index 06411a8..ae3ef0e 100644
--- a/libpldmresponder/fru.hpp
+++ b/libpldmresponder/fru.hpp
@@ -128,7 +128,7 @@
 {
 
   public:
-    Handler(const std::string configPath) : impl(configPath)
+    Handler(const std::string& configPath) : impl(configPath)
     {
         handlers.emplace(PLDM_GET_FRU_RECORD_TABLE_METADATA,
                          [this](const pldm_msg* request, size_t payloadLength) {