nfsd: don't set SVC_SOCK_ANONYMOUS when creating nfsd sockets

When creating nfsd sockets via the netlink interface, we do want to
register with the portmapper. Don't set SVC_SOCK_ANONYMOUS.

Reported-by: Steve Dickson <steved@redhat.com>
Fixes: 16a47117 ("NFSD: add listener-{set,get} netlink command")
Cc: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>