be consistent with return values in FindCache.Get
be consistent with return values in FindCache.Get

Co-Authored-By: woodsaj <a04edf16ec0490cec6a475b211ebe4383a3c40e2@grafana.com>
raintank/metrictank,replay/metrictank,raintank/metrictank,replay/metrictank,raintank/raintank-metric,raintank/metrictank,replay/metrictank,replay/metrictank,raintank/raintank-metric,raintank/metrictank,raintank/raintank-metric