treewide: Clean up string parameters

Change-Id: I0d3ea6a83465181d3edec1587ff824103489072e
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/src/system_configuration.cpp b/src/system_configuration.cpp
index a302ace..192f12d 100644
--- a/src/system_configuration.cpp
+++ b/src/system_configuration.cpp
@@ -24,7 +24,7 @@
     sdbusplus::xyz::openbmc_project::Network::server::SystemConfiguration;
 
 SystemConfiguration::SystemConfiguration(sdbusplus::bus_t& bus,
-                                         const std::string& objPath) :
+                                         stdplus::const_zstring objPath) :
     Iface(bus, objPath.c_str(), Iface::action::defer_emit),
     bus(bus)
 {