fix megacheck issue: simplified return err
fix megacheck issue: simplified return err

GoogleCloudPlatform/prometheus,alileza/prometheus,kangwoo/prometheus,prometheus/prometheus,alileza/prometheus,Gouthamve/prometheus,Gouthamve/prometheus,keegancsmith/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus,prometheus/tsdb,alileza/prometheus,Gouthamve/prometheus,GoogleCloudPlatform/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,prometheus/prometheus,kangwoo/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,kangwoo/prometheus,alileza/prometheus,prometheus/prometheus,keegancsmith/prometheus,prometheus/prometheus,keegancsmith/prometheus,Gouthamve/prometheus,kangwoo/prometheus,Gouthamve/tsdb,keegancsmith/prometheus