When we do not compile in the RF_ASSERT-ion code, still "use" the expression,

so the compiler does not warn about unused things.

sys/dev/raidframe/rf_general.h

@@ -1,4 +1,4 @@
-/*	$NetBSD: rf_general.h,v 1.19 2011/05/23 21:49:35 joerg Exp $	*/
+/*	$NetBSD: rf_general.h,v 1.20 2013/09/15 12:06:50 martin Exp $	*/
 /*
  * Copyright (c) 1995 Carnegie-Mellon University.
  * All rights reserved.
@@ -65,7 +65,7 @@ extern char rf_panicbuf[];
   } \
 }
 #else /* RAID_DIAGNOSTIC */
-#define RF_ASSERT(x) {/*noop*/}
+#define RF_ASSERT(x) { /*noop*/ (void)(x); }
 #endif /* RAID_DIAGNOSTIC */
 
 /* random stuff */