test: fix flaky test-inspector

Using `socket.destroy()` instead of `socket.end()` fixes
more-than-intermittent ECONNRESET issues on Windows.

PR-URL: https://github.com/nodejs/node/pull/9727
Fixes: https://github.com/nodejs/node/issues/8804
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Eugene Ostroukhov <eostroukhov@google.com>

test/inspector/inspector-helper.js

@@ -286,7 +286,7 @@ TestSession.prototype.disconnect = function(childDone) {
     this.expectClose_ = true;
     this.harness_.childInstanceDone =
         this.harness_.childInstanceDone || childDone;
-    this.socket_.end();
+    this.socket_.destroy();
     console.log('[test]', 'Connection terminated');
     callback();
   });

test/inspector/inspector.status

@@ -7,4 +7,3 @@ prefix inspector
 [true] # This section applies to all platforms
 
 [$system==win32]
-test-inspector  : PASS,FLAKY