ARCHITECTURE_DESC is unused, no need to error out for that.

Index: src/xpdev/genwrap.h
--- src/xpdev/genwrap.h.orig
+++ src/xpdev/genwrap.h
@@ -228,7 +228,7 @@ extern "C" {
 	#ifdef UNAME_ARCHITECTURE_DESC
 		#define ARCHITECTURE_DESC UNAME_ARCHITECTURE_DESC
 	#else
-		#error "Need to describe target architecture"
+		#define ARCHITECTURE_DESC "unknown"
 	#endif
 #endif
 
