Remove assert in vector rep
Remove assert in vector rep

Summary: This assert makes Insert O(n^2) instead of O(n) in debug mode. Memtable insert is in the critical path. No need to assert uniqunnes of the key here, since we're adding a sequence number to it anyway.

Test Plan: none

Reviewers: sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22443

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