Details:
- fixes the somewhat incorrect logic in KLineEditButton::animateVisible
- simplifies KLineEdit::updateClearButtonIcon consequently.
Testing
tested with klineedittest found in kdelibs/kdeui/tests, this with and without the patch attached to comment #1 of bug 268898, used to actually trigger the mentionned bug. Also tested with other klineEdit implementation such as Dolphin's location bar.