Cleanup: comments for is_path_builtin

Also reduce scope of import.

release/scripts/startup/bl_ui/space_filebrowser.py

@@ -432,7 +432,7 @@ class FILEBROWSER_MT_view(Menu):
 class FILEBROWSER_MT_select(Menu):
     bl_label = "Select"
 
-    def draw(self, context):
+    def draw(self, _context):
         layout = self.layout
 
         layout.operator("file.select_all", text="All").action = 'SELECT'