sstable-utils: use sharding_info::shard_of
sstable-utils: use sharding_info::shard_of

Create sharding_info with the same parameters as
the partitioner and use it instead of the partitioner.

Signed-off-by: Piotr Jastrzebski <2c0eb4a25a7cde333ff2d0860cb06051925fd74f@scylladb.com>

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