[inspector] finish test runner gracefully..

test/inspector/debugger/stepping-with-blackboxed-ranges.js

Index: test/inspector/debugger/stepping-with-blackboxed-ranges.js
diff --git a/test/inspector/debugger/stepping-with-blackboxed-ranges.js b/test/inspector/debugger/stepping-with-blackboxed-ranges.js
index 740634f68fe9372efd5a258b0c291eec3eb41dc5..0a97e5dc3555c1ad646df0649442d718e4c3a767 100644
--- a/test/inspector/debugger/stepping-with-blackboxed-ranges.js
+++ b/test/inspector/debugger/stepping-with-blackboxed-ranges.js
@@ -103,8 +103,10 @@ var actions = [ "stepOut", "print", "stepOut", "print", "stepOut", "print",
 function runAction(response)
 {
   var action = actions.shift();
-  if (!action)
+  if (!action) {
     InspectorTest.completeTest();
+    return;
+  }
 
   if (action === "print") {
     printCallFrames(response.params.callFrames);