common/flatpak-dir-private.h: Fix order of arguments
common/flatpak-dir-private.h: Fix order of arguments

This issue was introduced by commit 5da7a0411.

Fixes https://github.com/flatpak/flatpak/issues/2966

Closes: #2968
Approved by: matthiasclasen

flatpak/flatpak,matthiasclasen/flatpak,flatpak/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,flatpak/flatpak,matthiasclasen/flatpak,flatpak/flatpak,matthiasclasen/flatpak,flatpak/flatpak