Fix coding style in QBluetooth

Affected: QBluetooth, QBluetoothAddress, QBluetoothDeviceDiscoveryAgent,
QBluetoothDeviceInfo, QBluetoothHostInfo, QBluetoothLocalDevice

Change-Id: Ia5af61f87eafecfba56b75fa61b81014cdd38960
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>