Minor optimization for BufferedSeriesIterator: actually drop the samples falling outside of the new delta from the underlying sampleRing, when ReduceDelta is called. (#4849)
Minor optimization for BufferedSeriesIterator: actually drop the samples falling outside of the new delta from the underlying sampleRing, when ReduceDelta is called. (#4849)

Signed-off-by: Alin Sinpalean <ca82fdd1dd8d4beec0f5d75e77ad4be7ccc694a7@gmail.com>
prometheus/prometheus,prometheus/prometheus,keegancsmith/prometheus,prometheus/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,GoogleCloudPlatform/prometheus,Gouthamve/prometheus,Gouthamve/prometheus,kangwoo/prometheus,alileza/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,Gouthamve/prometheus,kangwoo/prometheus,Gouthamve/prometheus,alileza/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,kangwoo/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus,alileza/prometheus,keegancsmith/prometheus,kangwoo/prometheus,prometheus/prometheus