ZTS: Fix upgrade_readonly_pool

Update cleanup_upgrade to use destroy_dataset and destroy_pool
when performing cleanup.  These wrappers retry if the pool is busy
preventing occasional failures like those observed when running
tests upgrade_readonly_pool.  For example:

    SUCCESS: test enabled == enabled
    User accounting upgrade is not executed on readonly pool
    NOTE: Performing local cleanup via log_onexit (cleanup_upgrade)
    cannot destroy 'testpool': pool is busy
    ERROR: zpool destroy testpool exited 1

Reviewed-by: Ryan Moeller <[email protected]>
Reviewed-by: John Kennedy <[email protected]>
Reviewed-by: Igor Kozhukhov <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #9400 

0 files changed, 0 insertions, 0 deletions