MFC r348563: MFV r348551: 9862 fix typo in comment in vdev_impl.h
illumos/illumos-gate@84927f52bd837f6e4882a19e43fd026f1828d910
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Allan Jude <allanjude@freebsd.org>