ports/184227: games/xspacewarp: Fix build with clang

[wg at FreeBSD.org]

Synopsis: games/xspacewarp: Fix build with clang

Responsible-Changed-From-To: freebsd-ports-bugs->wg
Responsible-Changed-By: wg
Responsible-Changed-When: Tue Nov 26 20:37:24 UTC 2013
Responsible-Changed-Why: 
I'll take it.

http://www.freebsd.org/cgi/query-pr.cgi?pr=184227