DefaultKafkaProducerFactory.stop() doesn't change running state

[quaff]

https://github.com/spring-projects/spring-kafka/blob/master/spring-kafka/src/main/java/org/springframework/kafka/core/DefaultKafkaProducerFactory.java#L201

stop method should change running to false, it's better to use AtomicBoolean.compareAndSet() instead of volatile boolean

[artembilan]

That’s good catch!
Feel free to provide a fix as a contribution.

Thank you!

[quaff]

I have created PR#778