ios: fix kill when running on device

Change-Id: I2bd9a461c055ef8aa5f5ed9facc879def0078f6f
Task-number: QTCREATORBUG-13259
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>
Reviewed-by: Christian Stenger <christian.stenger@theqtcompany.com>
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@theqtcompany.com>

src/plugins/ios/iostoolhandler.cpp

@@ -286,7 +286,8 @@ void IosToolHandlerPrivate::stop(int errorCode)
         return;
     }
     if (process.state() != QProcess::NotRunning) {
-        process.terminate();
+        process.write("k\n\r");
+        process.closeWriteChannel();
         killTimer.start(1500);
     }
 }