Fix memory leak in cache_test introduced in the previous commit
Fix memory leak in cache_test introduced in the previous commit

Test Plan: Verified that valgrind build passes for cache_test

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D37665

NickCis/rocksdb,JoeWoo/rocksdb,sorphi/rocksdb,wskplho/rocksdb,tsheasha/rocksdb,ryneli/rocksdb,flabby/rocksdb,IMCG/RcoksDB,OverlordQ/rocksdb,bbiao/rocksdb,Andymic/rocksdb,norton/rocksdb,tizzybec/rocksdb,RyanTech/rocksdb,OverlordQ/rocksdb,wat-ze-hex/rocksdb,biddyweb/rocksdb,biddyweb/rocksdb,IMCG/RcoksDB,fengshao0907/rocksdb,dkorolev/rocksdb,hobinyoon/rocksdb,kaschaeffer/rocksdb,ryneli/rocksdb,vashstorm/rocksdb,Andymic/rocksdb,bbiao/rocksdb,luckywhu/rocksdb,lgscofield/rocksdb,biddyweb/rocksdb,SunguckLee/RocksDB,makelivedotnet/rocksdb,alihalabyah/rocksdb,hobinyoon/rocksdb,Vaisman/rocksdb,wat-ze-hex/rocksdb,Applied-Duality/rocksdb,geraldoandradee/rocksdb,JackLian/rocksdb,Applied-Duality/rocksdb,wskplho/rocksdb,kaschaeffer/rocksdb,rDSN-Projects/rocksdb.replicated,RyanTech/rocksdb,dkorolev/rocksdb,JackLian/rocksdb,OverlordQ/rocksdb,jalexanderqed/rocksdb,caijieming-baidu/rocksdb,anagav/rocksdb,wskplho/rocksdb,SunguckLee/RocksDB,IMCG/RcoksDB,sorphi/rocksdb,wlqGit/rocksdb,alihalabyah/rocksdb,rDSN-Projects/rocksdb.replicated,NickCis/rocksdb,rDSN-Projects/rocksdb.replicated,tizzybec/rocksdb,luckywhu/rocksdb,IMCG/RcoksDB,flabby/rocksdb,wenduo/rocksdb,geraldoandradee/rocksdb,bbiao/rocksdb,tsheasha/rocksdb,skunkwerks/rocksdb,NickCis/rocksdb,IMCG/RcoksDB,JackLian/rocksdb,dkorolev/rocksdb,tsheasha/rocksdb,jalexanderqed/rocksdb,wenduo/rocksdb,anagav/rocksdb,Applied-Duality/rocksdb,alihalabyah/rocksdb,jalexanderqed/rocksdb,jalexanderqed/rocksdb,zhangpng/rocksdb,caijieming-baidu/rocksdb,bbiao/rocksdb,vashstorm/rocksdb,JackLian/rocksdb,JoeWoo/rocksdb,skunkwerks/rocksdb,makelivedotnet/rocksdb,siddhartharay007/rocksdb,zhangpng/rocksdb,lgscofield/rocksdb,wenduo/rocksdb,fengshao0907/rocksdb,mbarbon/rocksdb,dkorolev/rocksdb,skunkwerks/rocksdb,vmx/rocksdb,flabby/rocksdb,norton/rocksdb,facebook/rocksdb,fengshao0907/rocksdb,vmx/rocksdb,luckywhu/rocksdb,kaschaeffer/rocksdb,wat-ze-hex/rocksdb,fengshao0907/rocksdb,wskplho/rocksdb,zhangpng/rocksdb,makelivedotnet/rocksdb,siddhartharay007/rocksdb,NickCis/rocksdb,mbarbon/rocksdb,ryneli/rocksdb,norton/rocksdb,JoeWoo/rocksdb,ylong/rocksdb,JoeWoo/rocksdb,facebook/rocksdb,jalexanderqed/rocksdb,hobinyoon/rocksdb,JackLian/rocksdb,anagav/rocksdb,alihalabyah/rocksdb,kaschaeffer/rocksdb,flabby/rocksdb,wlqGit/rocksdb,caijieming-baidu/rocksdb,facebook/rocksdb,vmx/rocksdb,vashstorm/rocksdb,biddyweb/rocksdb,temicai/rocksdb,ryneli/rocksdb,kaschaeffer/rocksdb,RyanTech/rocksdb,norton/rocksdb,luckywhu/rocksdb,vashstorm/rocksdb,vashstorm/rocksdb,fengshao0907/rocksdb,bbiao/rocksdb,anagav/rocksdb,rDSN-Projects/rocksdb.replicated,vmx/rocksdb,skunkwerks/rocksdb,geraldoandradee/rocksdb,geraldoandradee/rocksdb,wat-ze-hex/rocksdb,wlqGit/rocksdb,zhangpng/rocksdb,anagav/rocksdb,wat-ze-hex/rocksdb,tizzybec/rocksdb,kaschaeffer/rocksdb,rDSN-Projects/rocksdb.replicated,luckywhu/rocksdb,biddyweb/rocksdb,hobinyoon/rocksdb,Vaisman/rocksdb,geraldoandradee/rocksdb,Applied-Duality/rocksdb,lgscofield/rocksdb,ylong/rocksdb,temicai/rocksdb,skunkwerks/rocksdb,kaschaeffer/rocksdb,sorphi/rocksdb,norton/rocksdb,temicai/rocksdb,tsheasha/rocksdb,Applied-Duality/rocksdb,JoeWoo/rocksdb,Andymic/rocksdb,JohnPJenkins/rocksdb,Andymic/rocksdb,SunguckLee/RocksDB,mbarbon/rocksdb,Applied-Duality/rocksdb,flabby/rocksdb,flabby/rocksdb,fengshao0907/rocksdb,zhangpng/rocksdb,Vaisman/rocksdb,dkorolev/rocksdb,siddhartharay007/rocksdb,norton/rocksdb,wat-ze-hex/rocksdb,JohnPJenkins/rocksdb,JohnPJenkins/rocksdb,vmx/rocksdb,NickCis/rocksdb,IMCG/RcoksDB,tsheasha/rocksdb,Vaisman/rocksdb,facebook/rocksdb,Vaisman/rocksdb,Andymic/rocksdb,OverlordQ/rocksdb,wenduo/rocksdb,tizzybec/rocksdb,JohnPJenkins/rocksdb,wlqGit/rocksdb,wenduo/rocksdb,Applied-Duality/rocksdb,hobinyoon/rocksdb,JohnPJenkins/rocksdb,IMCG/RcoksDB,sorphi/rocksdb,bbiao/rocksdb,makelivedotnet/rocksdb,tsheasha/rocksdb,wenduo/rocksdb,JoeWoo/rocksdb,temicai/rocksdb,wat-ze-hex/rocksdb,makelivedotnet/rocksdb,anagav/rocksdb,caijieming-baidu/rocksdb,alihalabyah/rocksdb,vashstorm/rocksdb,temicai/rocksdb,biddyweb/rocksdb,fengshao0907/rocksdb,JohnPJenkins/rocksdb,wlqGit/rocksdb,JackLian/rocksdb,bbiao/rocksdb,ylong/rocksdb,hobinyoon/rocksdb,JoeWoo/rocksdb,sorphi/rocksdb,dkorolev/rocksdb,makelivedotnet/rocksdb,Andymic/rocksdb,wenduo/rocksdb,NickCis/rocksdb,vmx/rocksdb,SunguckLee/RocksDB,temicai/rocksdb,facebook/rocksdb,caijieming-baidu/rocksdb,alihalabyah/rocksdb,skunkwerks/rocksdb,wskplho/rocksdb,vmx/rocksdb,NickCis/rocksdb,sorphi/rocksdb,OverlordQ/rocksdb,RyanTech/rocksdb,SunguckLee/RocksDB,rDSN-Projects/rocksdb.replicated,ylong/rocksdb,JackLian/rocksdb,ryneli/rocksdb,ylong/rocksdb,hobinyoon/rocksdb,lgscofield/rocksdb,wlqGit/rocksdb,biddyweb/rocksdb,norton/rocksdb,sorphi/rocksdb,tizzybec/rocksdb,rDSN-Projects/rocksdb.replicated,Andymic/rocksdb,SunguckLee/RocksDB,Vaisman/rocksdb,anagav/rocksdb,dkorolev/rocksdb,ryneli/rocksdb,ryneli/rocksdb,mbarbon/rocksdb,geraldoandradee/rocksdb,jalexanderqed/rocksdb,tsheasha/rocksdb,ylong/rocksdb,luckywhu/rocksdb,caijieming-baidu/rocksdb,SunguckLee/RocksDB,Andymic/rocksdb,geraldoandradee/rocksdb,wskplho/rocksdb,siddhartharay007/rocksdb,tizzybec/rocksdb,SunguckLee/RocksDB,siddhartharay007/rocksdb,tsheasha/rocksdb,wskplho/rocksdb,vmx/rocksdb,facebook/rocksdb,mbarbon/rocksdb,wat-ze-hex/rocksdb,lgscofield/rocksdb,zhangpng/rocksdb,norton/rocksdb,vashstorm/rocksdb,lgscofield/rocksdb,hobinyoon/rocksdb,bbiao/rocksdb,RyanTech/rocksdb,caijieming-baidu/rocksdb,facebook/rocksdb,alihalabyah/rocksdb,flabby/rocksdb,temicai/rocksdb,tizzybec/rocksdb,RyanTech/rocksdb,OverlordQ/rocksdb,makelivedotnet/rocksdb,lgscofield/rocksdb,ylong/rocksdb,OverlordQ/rocksdb,Vaisman/rocksdb,mbarbon/rocksdb,wenduo/rocksdb,facebook/rocksdb,RyanTech/rocksdb,mbarbon/rocksdb,wlqGit/rocksdb,siddhartharay007/rocksdb,JohnPJenkins/rocksdb,skunkwerks/rocksdb,luckywhu/rocksdb,zhangpng/rocksdb,jalexanderqed/rocksdb,siddhartharay007/rocksdb