MFC r230005:

Use a reasonable-sized buffer when formatting error messages about
installing zoneinfo.  While we're in the vicinity, add some missing
error checking to eliminate an unhelpful error message when unlink()
fails.

/me is embarrassed by the quality of his 16-year-old code.
The whole thing is awful and could stand a complete rewrite.

PR:		164038
Submitted by:	Devin Teske (but implemented differently)