5984 zfs clone should not mount the clone if canmount == noauto

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Justin Gibbs <gibbs@scsiguy.com>
Reviewed by: Richard Elling <Richard.Elling@richardelling.com>
Approved by: Matthew Ahrens <mahrens@delphix.com>

illumos/illumos-gate@780828c8aa1df2dc6f2066107a4aa8d045297972