Avoid fall-through in test-container if execlp fails

[Florian Weimer]

* Joseph Myers:

> diff --git a/support/test-container.c b/support/test-container.c
> index a24b24c03b..ed911e33f9 100644
> --- a/support/test-container.c
> +++ b/support/test-container.c
> @@ -361,6 +361,7 @@ recursive_remove (char *path)
>    case 0:
>      /* Child.  */
>      execlp ("rm", "rm", "-rf", path, NULL);
> +    FAIL_EXIT1 ("exec rm: %m");
>    default:
>      /* Parent.  */
>      waitpid (child, &status, 0);

Looks good to me.