Always evaluate expression in BUG_ON() macro to avoid unused variable

warnings.  Makes non diagnostic kernel compile.
OK kettenis@

diff --git a/sys/dev/pci/drm/drm_linux.h b/sys/dev/pci/drm/drm_linux.h
index a7a2127..6110243 100644 (file)
--- a/sys/dev/pci/drm/drm_linux.h
+++ b/sys/dev/pci/drm/drm_linux.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: drm_linux.h,v 1.48 2016/10/08 05:52:06 guenther Exp $ */
+/*     $OpenBSD: drm_linux.h,v 1.49 2017/04/16 17:16:21 bluhm Exp $    */
 /*
  * Copyright (c) 2013, 2014, 2015 Mark Kettenis
  *
@@ -162,7 +162,11 @@ do {                                                                       \
        panic("BUG at %s:%d", __FILE__, __LINE__);                      \
 } while (0)
 
-#define BUG_ON(x) KASSERT(!(x))
+#ifndef DIAGNOSTIC
+#define BUG_ON(x)      ((void)(x))
+#else
+#define BUG_ON(x)      KASSERT(!(x))
+#endif
 
 #define BUILD_BUG_ON(x) CTASSERT(!(x))
 #define BUILD_BUG_ON_NOT_POWER_OF_2(x)