sstables: index_reader: Remove redundant function
sstables: index_reader: Remove redundant function

duarten/scylla,duarten/scylla,scylladb/scylla,avikivity/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,duarten/scylla,scylladb/scylla,avikivity/scylla