Fix memory leak

Fixes https://gitlab.freedesktop.org/libspectre/libspectre/issues/33, bug report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20283

Indentation is all over the damn place, VS Code and the GitLab editor has it lined up but not when you view the MR, I think the files are a mix of 8-wide tabs and spaces.