Fix a compilation error in ROCKSDB_LITE in db/internal_stats.h
Fix a compilation error in ROCKSDB_LITE in db/internal_stats.h

Summary:
Fix a compilation error in ROCKSDB_LITE in db/internal_stats.h

Other compilation errors will be fixed in a separate diff.

Test Plan: make OPT=-DROCKSDB_LITE

Reviewers: sdong, igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D36807

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