Commit 464e454e1c ("workqueue: rename wq->unbound_attrs to wq->attrs")
renamed wq->unbound_attrs to wq->attrs. When running wq_dump.py against
older running kernels or vmcores where struct workqueue_struct still
contains unbound_attrs, drgn raises an AttributeError.
Add a wq_attrs() helper to allow wq_dump.py to inspect both older and newer
kernel versions seamlessly.
Fixes: 464e454e1c ("workqueue: rename wq->unbound_attrs to wq->attrs")
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Signed-off-by: Tejun Heo <tj@kernel.org>