Add missing `executor.`

Change-Id: I397142388b27d7c66c90ce8f85c08457f872fc55
diff --git a/utils/misc/src/main/java/org/onlab/util/SharedExecutorService.java b/utils/misc/src/main/java/org/onlab/util/SharedExecutorService.java
index 2cfdb5a..051155c 100644
--- a/utils/misc/src/main/java/org/onlab/util/SharedExecutorService.java
+++ b/utils/misc/src/main/java/org/onlab/util/SharedExecutorService.java
@@ -127,7 +127,7 @@
     public <T> T invokeAny(Collection<? extends Callable<T>> tasks,
                            long timeout, TimeUnit unit)
             throws InterruptedException, ExecutionException, TimeoutException {
-        return invokeAny(tasks, timeout, unit);
+        return executor.invokeAny(tasks, timeout, unit);
     }
 
     @Override