In TabBarAnimation::updateState() the wrong parameter was used to
determine if the animation has stopped or not. This lead to a call to
moveTabFinished() when the animation started and not when it was
finished.
Task-number: QTBUG-42951
Change-Id: I213c7f5e863a9a4e33bd472de93933efebf63fc7
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>