Partition handler fails updating tables with partitioning
based on timestamp field, as it calculates the timestamp field
AFTER it calculates the number of partition of a record.

Fixed by adding timestamp_field->set_time() call and disabling
such consequent calls


mysql-test/r/partition.result:
  Bug #32067 Partitions: crash with timestamp column.
  
  test result
mysql-test/t/partition.test:
  Bug #32067 Partitions: crash with timestamp column.
  
  test case
sql/ha_partition.cc:
  Bug #32067 Partitions: crash with timestamp column.
  
  do timestamp_field->set_time() in the ha_partition::update_row()