ZTS: checkpoint_discard_busy does not set 16M on cleanup
Originally hex value is used as decimal.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Toomas Soome <tsoome@me.com>
Closes #16917