[PATCH] build: Used FAIL_EXIT1 () on failure to exec child [BZ #23990]

[Girish Joshi]

> LGTM, thanks.
>
> I will push it upstream for you.
>
> Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

Thanks Adhemerval.

Girish Joshi