Tidy up more Cleaner.clean() is called.

Author: peter-lawrey

chronicle/src/test/java/net/openhft/chronicle/TestTaskExecutionUtil.java

@@ -76,7 +76,8 @@ public void run() {
             try {
                 task.call();
             } catch (Throwable e) {
-                failure = new AssertionError("Task failed", e);
+                failure = new AssertionError("Task failed");
+                failure.initCause(e);
             }
         }