Bluetooth: 6lowpan: Set the peer IPv6 address correctly

The peer IPv6 address contained wrong U/L bit in the EUI-64 part.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org # 3.17.x