Bluetooth: Fix notifying about cancelled connection attempt

If LE Create Connection was cancelled LE Connection Complete event
status is set to Unknown Connection Identifier and doesn't contain
valid remote address. In such case we need to look for connection
object in CONNECT state without using address. There can be only one
object in that state anyway so this is OK also for other error codes.

Change-Id: Ie61d47b8bb7ade6b2ab4db14ee394a65bb4e642b
Signed-off-by: Szymon Janc <ext.szymon.janc@tieto.com>