tidy: fix performance-unnecessary-value-param

Tested by building mapperx.

Change-Id: Ib8c3f52e437a13de75f934bb17605dd8527bb15b
Signed-off-by: Brad Bishop <bradbish@qti.qualcomm.com>
diff --git a/src/main.cpp b/src/main.cpp
index b5dc37f..bf2bd48 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -260,7 +260,7 @@
     InterfaceMapType& interfaceMap, const std::string& processName,
     AssociationMaps& assocMaps,
 #ifdef MAPPER_ENABLE_DEBUG
-    std::shared_ptr<std::chrono::time_point<std::chrono::steady_clock>>
+    const std::shared_ptr<std::chrono::time_point<std::chrono::steady_clock>>&
         globalStartTime,
 #endif
     sdbusplus::asio::object_server& objectServer)