folderlistmodel holds the folder open even after changing, prevents ejecting removable devices

qt.labs.folderlistmodel:
change 'folder' will not free old 'folder', it looks like it still watch old 'folder', which result in:
we can't eject removable usb storage.

after checked the src code, I found that removePath and setPath used different parameter, maybe they should all use 'd->currentDir.path()' or all use resolved path as parameter:

void QQuickFolderListModel::setFolder(const QUrl &folder)
{
......
    QString resolvedPath = QQuickFolderListModelPrivate::resolvePath(folder);
.......
        d->fileInfoThread.removePath(d->currentDir.path());

    d->currentDir = folder;
......
    d->fileInfoThread.setPath(resolvedPath);
}