update: linear_score_ftrl.cc
update: linear_score_ftrl.cc

PKU-Cloud-Lab/xLearn,aksnzhy/xLearn,PKU-Cloud-Lab/xLearn,aksnzhy/xLearn,aksnzhy/xLearn,PKU-Cloud-Lab/xLearn,aksnzhy/xLearn,PKU-Cloud-Lab/xLearn