MFV r337193:
9424 ztest failure: "unprotected error in call to Lua API (Invalid value type 'f
unction' for key 'error')"

illumos/illumos-gate@fe3ba4d1227d8746116ece7240682b13595c3142

Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Don Brady <don.brady@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Matthew Ahrens <mahrens@delphix.com>