OpenZFS 7180 - potential race between zfs_suspend_fs+zfs_resume_fs and zfs_ioc_rename

Authored by: Andriy Gapon <andriy.gapon@clusterhq.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: George Melikov <mail@gmelikov.ru>

OpenZFS-issue: https://www.illumos.org/issues/7180
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/690041b
Closes #5627