There is a single remaining user in qemu-img, and another one in a test
case, both of which can be trivially converted to using BlockJob.blk
instead.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>