switch experimental::fs to std::fs

std::filesystem was added to C++17 and is well supported now.  Remove
the older std::experimental::filesystem usage.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I8bc4db47b259906f91ea51321c4e9ee1c34ca31f
diff --git a/7seg.cpp b/7seg.cpp
index 4c9f273..2efc25c 100644
--- a/7seg.cpp
+++ b/7seg.cpp
@@ -16,13 +16,13 @@
 
 #include <cstdint>
 #include <cstdio>
-#include <experimental/filesystem>
+#include <filesystem>
 #include <lpcsnoop/snoop_listen.hpp>
 #include <string>
 
 static const char* device_node_path;
 
-namespace fs = std::experimental::filesystem;
+namespace fs = std::filesystem;
 
 static void DisplayDbusValue(postcode_t postcodes)
 {
diff --git a/meson.build b/meson.build
index 8959cfb..4655c16 100644
--- a/meson.build
+++ b/meson.build
@@ -83,9 +83,6 @@
       sdbusplus,
       phosphor_dbus_interfaces,
     ],
-    link_args : [
-      '-lstdc++fs',
-    ],
     install: true,
   )
 endif