Actually return the correct upload data for testing

Author: vietj

vertx-core/src/test/java/io/vertx/tests/http/fileupload/HttpClientFileUploadTest.java

@@ -312,6 +312,7 @@ private List<Upload> testFileUploadFormMultipart(
       });
       req.endHandler(v -> {
         req.response().end();
+        checker.accept(req);
       });
     });
     startServer();
@@ -323,7 +324,7 @@ private List<Upload> testFileUploadFormMultipart(
         .compose(HttpClientResponse::body))
       .await();
 
-    return toUpload;
+    return uploads;
   }
 
   static class Upload {