Bluetooth: Fix handling of L2CAP Command Reject over LE

If we receive an L2CAP command reject message over LE we should take
appropriate action on the corresponding channel. This is particularly
important when trying to interact with a remote pre-4.1 system using LE
CoC signaling messages. If we don't react to the command reject the
corresponding socket would not be notified until a connection timeout
occurs.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>