mdb ::refcount dcmd no longer works
Review Request #2452 - Created Nov. 12, 2019 and submitted - Latest diff uploaded
After 'refcount_t' was renamed to 'zfs_recount_t' to facilitate porting of ZoL changes, the mdb dcmd was never updated. This fixes it (and renames it to match the new type).
Used this change to troubleshoot #11947