replace fs alias with std::filesystem

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I9072353526c2c18453aa97dc6f9c5d610508609a
diff --git a/ramoops_manager.cpp b/ramoops_manager.cpp
index acd3598..57250cc 100644
--- a/ramoops_manager.cpp
+++ b/ramoops_manager.cpp
@@ -23,10 +23,8 @@
 
 Manager::Manager(const std::string& filePath)
 {
-    namespace fs = std::filesystem;
-
-    fs::path dir(filePath);
-    if (!fs::exists(dir) || fs::is_empty(dir))
+    std::filesystem::path dir(filePath);
+    if (!std::filesystem::exists(dir) || std::filesystem::is_empty(dir))
     {
         return;
     }