perf trace beauty: Fix generation of errno id->str table on ALT Linux

For some reason using:

         cat <<EoFuncBegin
  static const char *errno_to_name__$arch(int err)
  {
         switch (err) {
  EoFuncBegin

In tools/perf/trace/beauty/arch_errno_names.sh isn't working on ALT
Linux sisyphus (development version), which could be some distro
specific glitch, so just get this done in an alternative way that works
everywhere while giving notice to the people working on that distro to
try and figure our what really took place.

Cc: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>