Fix race in bufferedBytes access
Fix race in bufferedBytes access

jimmykuo/sarama,betable/sarama,jimmykuo/sarama,VividCortex/sarama,raisemarketplace/sarama,HelixEducation/sarama,gyroscope-innovations/legacy_sarama,jepst/sarama,aybabtme/sarama,mailgun/sarama,kraveio/sarama,yangfan876/sarama,HelixEducation/sarama,kmiku7/sarama,scalingdata/sarama,pronix/sarama,crast/sarama,Neuw84/sarama,rafrombrc/sarama,remerge/sarama,Shopify/sarama,gyroscope-innovations/legacy_sarama,VividCortex/sarama,Shopify/sarama,betable/sarama,winlinvip/sarama,aybabtme/sarama,remerge/sarama,Neuw84/sarama,kraveio/sarama,DataDog/sarama,vrischmann/sarama,pronix/sarama,LastManStanding/sarama,vrischmann/sarama,crast/sarama,cep21/sarama,LastManStanding/sarama,yangfan876/sarama,uovobw/sarama,winlinvip/sarama,rafrombrc/sarama,mailgun/sarama,DataDog/sarama,raisemarketplace/sarama,kmiku7/sarama,cep21/sarama,scalingdata/sarama,uovobw/sarama,jepst/sarama