panic when in zfs_fuid_create_cred() when userid is negative. It is
converted to unsigned value which makes IS_EPHEMERAL() macro to
incorrectly report that this is ephemeral ID. The most reasonable
solution for now is to always report that the given ID is not ephemeral.
PR: kern/132337
Submitted by: Matthew West <freebsd@r.zeeb.org>
Tested by: Thomas Backman <serenity@exscape.org>, Michael Reifenberger <mike@reifenberger.com>
Approved by: re (kib)
MFC after: 2 weeks