In the ha_partition::position() we didn't calculate the number
of the partition of the record. We used m_last_part value instead,
relying on that it is set in other place like previous call of a method
like ::write_row(). In replication we don't call any of these befor
position(). Delete_rows_log_event::do_exec_row calls find_and_fetch_row.
In case of InnoDB-based PARTITION table, we have HA_PRIMARY_KEY_REQUIRED_FOR_POSITION
enabled, so use position() / rnd_pos() calls to fetch the record.

Fixed by adding partition_id calculation to the ha_partition::position()