OpenZFS 9616 - Bogus error when attempting to set property on read-only pool
Authored by: Andrew Stormont <astormont@racktopsystems.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
OpenZFS-issue: https://illumos.org/issues/9616
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/f62db44d
Closes #7974