The new NFS server would not allow a hard link to be
created to a symlink. This restriction (which was
inherited from OpenBSD) is not required by the NFS RFCs.
Since this is allowed by the old NFS server, it is a
POLA violation to not allow it. This patch modifies the
new NFS server to allow this.

Reported by:	jhb
Reviewed by:	jhb
MFC after:	3 days

Ticket:		#5165

(cherry picked from commit 579917b4943fd0fd6058050ec288a72fb7fe3bb4)