commitlog_replayer: Fix broken comparison
commitlog_replayer: Fix broken comparison

A commitlog entry should be ignored if its position is <= highest recorded
position, not <.

scylladb/scylla,scylladb/scylla,kjniemi/scylla,raphaelsc/scylla,raphaelsc/scylla,avikivity/scylla,scylladb/scylla,avikivity/scylla,duarten/scylla,duarten/scylla,raphaelsc/scylla,avikivity/scylla,duarten/scylla,kjniemi/scylla,scylladb/scylla,kjniemi/scylla