Fix .NET resource leak detection leaked type lost (#1446)

Summary:
Hi all,

This is just a small fix tries to resolve the leaked type lost issue. It was excluded from previous CIL race condition PR due to irrelevance.

Thanks!

Pull Request resolved: https://github.com/facebook/infer/pull/1446

Reviewed By: skcho

Differential Revision: D28566755

Pulled By: ngorogiannis

fbshipit-source-id: 1c9938d9c

infer/src/dotnet/ResourceLeakCSDomain.ml

@@ -97,7 +97,9 @@ let release_resource access_path held =
   let old_count = find_count access_path held in
   let remove_resource_from_hash =
     match old_count with
-    | NonTop count when count < 2 ->
+    | Top ->
+        Hashtbl.remove !type_map access_path
+    | NonTop count when count <= 0 ->
         Hashtbl.remove !type_map access_path
     | _ ->
         ()