[PATCH v2] linux: wait4: Fix incorrect return value comparison

[Florian Weimer]

* Alistair Francis via Libc-alpha:

> Path 600f00b "linux: Use long time_t for wait4/getrusage" introduced

Typo: "Path"

> two bugs:
>  - The usage32 struct was set if the wait4 syscall had an error.
>  - For 32-bit systems the usage struct was set even if it was specified
>    as NULL.
>
> This patch fixes the two issues.

Would it make sense to include a test case?

(Somehow, my earlier message did not make it it to the list.)

Thanks,
Florian