Fix warning

src/lib/Concrete/DirEnumerable.vala

@@ -3,12 +3,10 @@ namespace Invercargill {
 
     internal class DirEnumerable : Enumerable<string> {
 
-        private string path;
-        private uint flags;
+        private Dir dir;
 
-        public DirEnumerable(string path, uint flags = 0) {
-            this.path = path;
-            this.flags = flags;
+        public DirEnumerable(owned Dir dir) {
+            this.dir = (owned)dir;
         }
 
         //  public override bool iterate_if (Invercargill.PredicateDelegate<T> handler) {
@@ -24,8 +22,6 @@ namespace Invercargill {
         //  }
 
         public override Tracker<string> get_tracker() {
-            var dir = Dir.open(path, flags);
-
             return new AdvanceTracker<string>((out obj) => {
                 var name = dir.read_name();
                 if(name != null) {