! doesn't do what we want in bash -e. Use a more explicit helper
instead, and specify expected error codes.
Signed-off-by: Josh Durgin <jdurgin@redhat.com>
Require that the pool name be passed twice along with an force option
before we irreversibly delete an entire pool of objects.
Signed-off-by: Sage Weil <sage@inktank.com>
