Fix memory leak in check_disk()
Reviewed-by: Allan Jude <allanjude@freebsd.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>
Closes #8897
Closes #8911