filesystem: use non-experimental version

std::experimental::filesystem has been deprecated since at least
C++17.  Switch to the std::filesystem one.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I7717a804a3d5c96f8717764c088529d65ad4e96c
diff --git a/chassis_state_manager.hpp b/chassis_state_manager.hpp
index 7d10c2a..1dc7716 100644
--- a/chassis_state_manager.hpp
+++ b/chassis_state_manager.hpp
@@ -12,7 +12,7 @@
 #include <sdeventplus/utility/timer.hpp>
 
 #include <chrono>
-#include <experimental/filesystem>
+#include <filesystem>
 #include <functional>
 
 namespace phosphor
@@ -26,7 +26,7 @@
     sdbusplus::xyz::openbmc_project::State::server::Chassis,
     sdbusplus::xyz::openbmc_project::State::server::PowerOnHours>;
 namespace sdbusRule = sdbusplus::bus::match::rules;
-namespace fs = std::experimental::filesystem;
+namespace fs = std::filesystem;
 
 /** @class Chassis
  *  @brief OpenBMC chassis state management implementation.
diff --git a/host_state_manager.cpp b/host_state_manager.cpp
index b098857..78899a0 100644
--- a/host_state_manager.cpp
+++ b/host_state_manager.cpp
@@ -46,7 +46,7 @@
 namespace osstatus =
     sdbusplus::xyz::openbmc_project::State::OperatingSystem::server;
 using namespace phosphor::logging;
-namespace fs = std::experimental::filesystem;
+namespace fs = std::filesystem;
 using sdbusplus::xyz::openbmc_project::Common::Error::InternalFailure;
 
 constexpr auto ACTIVE_STATE = "active";
diff --git a/host_state_manager.hpp b/host_state_manager.hpp
index 0e796f5..1e9bb10 100644
--- a/host_state_manager.hpp
+++ b/host_state_manager.hpp
@@ -13,7 +13,7 @@
 #include <xyz/openbmc_project/State/Boot/Progress/server.hpp>
 #include <xyz/openbmc_project/State/OperatingSystem/Status/server.hpp>
 
-#include <experimental/filesystem>
+#include <filesystem>
 #include <functional>
 #include <string>
 
@@ -33,7 +33,7 @@
 PHOSPHOR_LOG2_USING;
 
 namespace sdbusRule = sdbusplus::bus::match::rules;
-namespace fs = std::experimental::filesystem;
+namespace fs = std::filesystem;
 
 /** @class Host
  *  @brief OpenBMC host state management implementation.
diff --git a/host_state_manager_main.cpp b/host_state_manager_main.cpp
index 186e06b..b96cdbf 100644
--- a/host_state_manager_main.cpp
+++ b/host_state_manager_main.cpp
@@ -8,7 +8,7 @@
 
 #include <cstdlib>
 #include <exception>
-#include <experimental/filesystem>
+#include <filesystem>
 #include <iostream>
 
 int main(int argc, char** argv)
@@ -33,7 +33,7 @@
         }
     }
 
-    namespace fs = std::experimental::filesystem;
+    namespace fs = std::filesystem;
 
     auto bus = sdbusplus::bus::new_default();