Put end of run staleness handler in seperate function.
Put end of run staleness handler in seperate function.

Improve log message.

brancz/prometheus,AlekSi/prometheus,keegancsmith/prometheus,prometheus/prometheus,AlekSi/prometheus,Gouthamve/prometheus,yanghongkjxy/prometheus,AlekSi/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,Gouthamve/prometheus,AlekSi/prometheus,Stackdriver/stackdriver-prometheus,yanghongkjxy/prometheus,Conorbro/prometheus,amorken/prometheus,Stackdriver/stackdriver-prometheus,keegancsmith/prometheus,GoogleCloudPlatform/prometheus,kangwoo/prometheus,brancz/prometheus,yanghongkjxy/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,Conorbro/prometheus,amorken/prometheus,alileza/prometheus,prometheus/prometheus,Stackdriver/stackdriver-prometheus,Stackdriver/stackdriver-prometheus,amorken/prometheus,keegancsmith/prometheus,alileza/prometheus,brancz/prometheus,keegancsmith/prometheus,Conorbro/prometheus,Gouthamve/prometheus,yanghongkjxy/prometheus,Conorbro/prometheus,keegancsmith/prometheus,Gouthamve/prometheus,kangwoo/prometheus,kangwoo/prometheus,prometheus/prometheus,prometheus/prometheus,kangwoo/prometheus,brancz/prometheus,amorken/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus