Snippets for git 2.55.0 from Fedora s390x

Sourced from https://kojipkgs.fedoraproject.org/packages/git/2.55.0/1.fc45/data/logs/s390x/build.log.

• reftable/stack.c:486:12: warning: ‘err’ may be used uninitialized [-Wmaybe-uninitialized]
    486 |         if (!err && fd >= 0 && !fstat(fd, &st->list_st) &&
        |            ^