Illumos 6268 - zfs diff confused by moving a file to another directory

6268 zfs diff confused by moving a file to another directory
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Justin Gibbs <gibbs@scsiguy.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:

https://www.illumos.org/issues/6268
https://github.com/illumos/illumos-gate/commit/aab0441

Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>