Fix QLEController::connectToDevice() documentation

A logical condition was inverted.

Change-Id: Ia7b54fe75a8cea4275e3c92c6283bc12f3423b64
Reviewed-by: Timur Pocheptsov <Timur.Pocheptsov@digia.com>
Reviewed-by: Alex Blasche <alexander.blasche@theqtcompany.com>