fix data race

[Littleiii]

What is the purpose of the change

fix data race

Previous read at 0x00c00013bd08 by goroutine 129: [github.com/apache/rocketmq-client-go/v2/internal.(rmqClient).InvokeSync()](http://github.com/apache/rocketmq-client-go/v2/internal.(rmqClient).InvokeSync()) /Users/xxx/go/pkg/mod/github.com/apache/rocketmq-client-go/v2@v2.1.2/internal/client.go:576 +0x95 [github.com/apache/rocketmq-client-go/v2/consumer.(defaultConsumer).findConsumerList()](http://github.com/apache/rocketmq-client-go/v2/consumer.(defaultConsumer).findConsumerList()) /Users/xxx/go/pkg/mod/github.com/apache/rocketmq-client-go/v2@v2.1.2/consumer/consumer.go:952 +0x25b [github.com/apache/rocketmq-client-go/v2/consumer.(defaultConsumer).doBalance.func1()](http://github.com/apache/rocketmq-client-go/v2/consumer.(defaultConsumer).doBalance.func1()) /Users/xxx/go/pkg/mod/github.com/apache/rocketmq-client-go/v2@v2.1.2/consumer/consumer.go:393 +0x164 sync.(Map).Range() /usr/local/Cellar/go/1.19/libexec/src/sync/map.go:354 +0x225 [github.com/apache/rocketmq-client-go/v2/consumer.(defaultConsumer).doBalance()](http://github.com/apache/rocketmq-client-go/v2/consumer.(*defaultConsumer).doBalance()) /Users/xxx/go/pkg/mod/github.com/apache/rocketmq-client-go/v2@v2.1.2/consumer/consumer.go:370 +0x56 [github.com/apache/rocketmq-client-go/v2/consumer.(defaultConsumer).doBalanceIfNotPaused()](http://github.com/apache/rocketmq-client-go/v2/consumer.(defaultConsumer).doBalanceIfNotPaused()) /Users/xxx/go/pkg/mod/github.com/apache/rocketmq-client-go/v2@v2.1.2/consumer/consumer.go:366 +0x117 [github.com/apache/rocketmq-client-go/v2/consumer.(pushConsumer).RebalanceIfNotPaused()](http://github.com/apache/rocketmq-client-go/v2/consumer.(pushConsumer).RebalanceIfNotPaused()) /Users/xxx/go/pkg/mod/github.com/apache/rocketmq-client-go/v2@v2.1.2/consumer/push_consumer.go:335 +0x3d [github.com/apache/rocketmq-client-go/v2/internal.(rmqClient).RebalanceIfNotPaused.func1()](http://github.com/apache/rocketmq-client-go/v2/internal.(rmqClient).RebalanceIfNotPaused.func1()) /Users/xxx/go/pkg/mod/github.com/apache/rocketmq-client-go/v2@v2.1.2/internal/client.go:879 +0x48 sync.(Map).Range() /usr/local/Cellar/go/1.19/libexec/src/sync/map.go:354 +0x225 [github.com/apache/rocketmq-client-go/v2/internal.(rmqClient).RebalanceIfNotPaused()](http://github.com/apache/rocketmq-client-go/v2/internal.(*rmqClient).RebalanceIfNotPaused()) /Users/xxx/go/pkg/mod/github.com/apache/rocketmq-client-go/v2@v2.1.2/internal/client.go:877 +0x95 [github.com/apache/rocketmq-client-go/v2/internal.GetOrNewRocketMQClient.func1()](http://github.com/apache/rocketmq-client-go/v2/internal.GetOrNewRocketMQClient.func1()) /Users/xxx/go/pkg/mod/github.com/apache/rocketmq-client-go/v2@v2.1.2/internal/client.go:231 +0x125 [github.com/apache/rocketmq-client-go/v2/internal/remote.(remotingClient).processCMD.func2()](http://github.com/apache/rocketmq-client-go/v2/internal/remote.(remotingClient).processCMD.func2()) /Users/xxx/go/pkg/mod/github.com/apache/rocketmq-client-go/v2@v2.1.2/internal/remote/remote_client.go:244 +0x95 [github.com/apache/rocketmq-client-go/v2/primitive.WithRecover()](http://github.com/apache/rocketmq-client-go/v2/primitive.WithRecover()) /Users/xxx/go/pkg/mod/github.com/apache/rocketmq-client-go/v2@v2.1.2/primitive/base.go:100 +0x48 [github.com/apache/rocketmq-client-go/v2/internal/remote.(remotingClient).processCMD.func4()](http://github.com/apache/rocketmq-client-go/v2/internal/remote.(remotingClient).processCMD.func4()) /Users/xxx/go/pkg/mod/github.com/apache/rocketmq-client-go/v2@v2.1.2/internal/remote/remote_client.go:243 +0x39