MDEV-16249 CHECKSUM TABLE for a spider table is not parallel and saves all data in memory in the spider head by default (#1328)

followup for be5c432a

ha_partition::calculate_checksum() has to invoke calculate_checksum()
for partitions unconditionally, not under (HA_HAS_OLD_CHECKSUM | HA_HAS_NEW_CHECKSUM).
Because the server uses ::info() to ask for a live checksum, while
calculate_checksum() must, precisely, calculate it the slow way,
also for tables that don't have the live checksum at all.

Also, fix the compilation on Windows (ha_checksum/ulonglong type mix).