[PATCH 10/12] Warn when gettimeofday is called with non-null tzp argument.

[Paul Eggert]

Zack Weinberg wrote:
> -    memset (tz, 0, sizeof *tz);
> +    memset (tz, 0, sizeof (struct timezone));

This change isn't necessary, and I prefer the previous version as it's easier to 
audit.