We know what engine we're using, so don't go the long way around via
QFileInfo and QFSFileEngine to get back to QFileSystemEngine in order to
calculate an absolute and clean path.
Since we're doing that, we may as well use QFileSystemEntry's ability to
give us the file name portion of this absolute path without having to go
via QFileInfo and QDir again. We just need to make sure that a dir name
isn't ending in a slash: absoluteName() would remove that for us, but
only if the entry isn't already absolute and clean.
Change-Id: I9d43e5b91eb142d6945cfffd17871389d359e750
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
61d99530c8