Fix CLANG build for db_bench
Fix CLANG build for db_bench

Summary: CLANG was broken for a recent change in db_ench. Fix it.

Test Plan: Build db_bench using CLANG.

Reviewers: rven, igor, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D30801

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