Remove a check for merge operator in builder.cc
Remove a check for merge operator in builder.cc

Summary:
Previously, builder.cc has a check for merge operator which prevents
RocksDB from crash when reopening a DB w/o properly specifying the merge
operator.  However, currently we observed a memory leak on failing in
RocksDB recovery.  This diff removes such check and let it crash instead of
causing memory leak for now before we have identified the real cause of
the memory leak.

Test Plan: make all check

Reviewers: sdong

Subscribers: ljin, igor

Differential Revision: https://reviews.facebook.net/D20913

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