Without this, pmu-events.c would be generated with variations in
ordering depending on non-deterministic filesystem readdir order.

I tested that pmu-events.c still has the same number of lines and that
perf list output works.

This patch was done while working on reproducible builds for openSUSE,
but also solves issues in Debian [1] and other distributions.

[1] https://tests.reproducible-builds.org/debian/rb-pkg/unstable/i386/linux.htmlSigned-off-by: Bernhard M. Wiedemann <bwiedemann@suse.de>
Cc: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20230321063032.19804-1-bwiedemann@suse.deSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>