Modify build_detect_platform to run fbcode.*.* irrespective of $PATH
Modify build_detect_platform to run fbcode.*.* irrespective of $PATH

Summary: This caused crash when the jenkins machine changed because the PATH variable is different.

Test Plan: make

Reviewers: dhruba, sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10803

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