replace fs alias with std::filesystem

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I9072353526c2c18453aa97dc6f9c5d610508609a
diff --git a/ramoops_manager_main.cpp b/ramoops_manager_main.cpp
index b737230..6adfef1 100644
--- a/ramoops_manager_main.cpp
+++ b/ramoops_manager_main.cpp
@@ -7,8 +7,8 @@
 
 int main()
 {
-    fs::path filePath(SYSTEMD_PSTORE_PATH);
-    if (!fs::exists(filePath))
+    std::filesystem::path filePath(SYSTEMD_PSTORE_PATH);
+    if (!std::filesystem::exists(filePath))
     {
         lg2::error("Pstore file path is not exists, FILE_PATH: {FILE_PATH}",
                    "FILE_PATH", filePath);