VSOCK: Remove hypervisor-only socket option

Remove hypervisor-only socket option.

Reported-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Andy King <acking@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>