[PATCH app-xcalc] Assume signal handlers return void, as C89 requires

[Gaetan Nadon]

On 13-12-16 02:04 PM, Mark Kettenis wrote:
> Not sure what you mean by that.  I certainly can't find signal_t in
> any of OpenBSD 's header files.  Anyway, this diff is:
I googled "signal_t VAX BSD" and I got scared :-)

I knew it was safe to remove, but I thought it might be an old
convention or coding style.

I'll do it later then. Thanks for the review.