Remove references to experimental filesystem

We're at CPP17 everywhere now, no need to keep the
experimental refrerence.

Tested: It builds

Change-Id: I2a3d13ff806261a47da0493be2f24a2b0c361c9f
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/src/Utils.cpp b/src/Utils.cpp
index 160e9fe..06d2549 100644
--- a/src/Utils.cpp
+++ b/src/Utils.cpp
@@ -14,9 +14,8 @@
 // limitations under the License.
 */
 
-#include "filesystem.hpp"
-
 #include <Utils.hpp>
+#include <filesystem>
 #include <fstream>
 #include <regex>
 #include <sdbusplus/bus/match.hpp>