linux-yocto/4.1: Bluetooth:Fix the connection fail of 6lowpan over BT LE

Backporting the 4.4 fix for 6lowpan:

   Author: Wu Zheng <wu.zheng@intel.com>
   Date:   Fri Nov 20 13:25:57 2015 +0800

       Bluetooth:Fix the connection fail of 6lowpan over BT LE

       When two devices with 6lowpan over BT LE connect each other,
       6lowpan over BT LE channel is set up between the two devices.
       However, the status of channel is not right.
       It always is set to CONNECTED and the channel can't be created.

       The status of channel need to be removed when connection is created.

       (The patch's reference from
       b0c09f94ff1660a1873549b788c998284ea5fb8a)

Signed-off-by: Wu Zheng <wu.zheng@intel.com>

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>