Refine the checks in InfoLogLevel test.
Refine the checks in InfoLogLevel test.

Summary:
InfoLogLevel test now checks the number of lines of the output log file
instead of the number of bytes in the log file.

This diff fixes the issue that the previous InfoLogLevel test in
auto_roll_logger_test passed in make check but fails when valgrind
is used.

Test Plan: run with make check and valgrind.

Reviewers: kailiu

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16407

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