aggregator_expire: don't lose bucket entries and sizes
aggregator_expire: don't lose bucket entries and sizes

when we rotate the buckets, we now need to take care of the possible
entries we have such that we don't lose an (allocated) pointer

piotr1212/carbon-c-relay,grobian/carbon-c-relay,piotr1212/carbon-c-relay,grobian/carbon-c-relay,piotr1212/carbon-c-relay,piotr1212/carbon-c-relay,grobian/carbon-c-relay