Commit 9e1db51d4b made nvmecontrol devlist get list of active
namespaces from the device instead of iterating through all possible
IDs. The problem is that this request is not supported before NVMe
1.1, and in particular by Intel Optane 905P drives. This change
reintroduces iteration for devices before NVMe 1.2.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D58010
Alexander Motin
86182d8902