Remove schedstat optimization, it is unreliable

[fastcat]

fixes: #444

[tsujan]

You mean that the issue described in #444 is because of the following condition?

        if ((sbuf = read_proc_file2(path, "schedstat")) == nullptr)
            return -1;

I think the patch makes sense, but it should be investigated thoroughly.

It may also be related to #447.

[fastcat]

You mean that the issue described in #444 is because of the following condition?

Yes.

I think the patch makes sense, but it should be investigated thoroughly.

I agree it seems strange, but I checked my systems and the contents of schedstat just ... don't change very often for some processes, even though they are consuming CPU time, etc.

It may also be related to #447.

That issue does match the symptoms I saw in #444 and applying this patch makes them go away for me, yes.

[tsujan]

It seems good to me. If a problem arises, we could reverse or change it.

Thanks!