Fix conditional jump based on an uninitialized value.

QElapsedTimer is POD and it is not initialized by default.

Change-Id: Ie6997e1c4225b9ba584de52cc0c9647f26e45438
Reviewed-by: Mitch Curtis <mitch.curtis@digia.com>
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>