Snippets for flatpak 1.18.1 from Alpine s390x

Sourced from https://build.alpinelinux.org/buildlogs/build-edge-s390x/community/flatpak/flatpak-1.18.1-r0.log.

• ../common/flatpak-prune.c:655:6: warning: 'exists' may be used uninitialized [-Wmaybe-uninitialized]
    655 |   if (!exists)
        |      ^