The default CONFIG_BUG=n version of BUG() should have an empty do...while

The default CONFIG_BUG=n version of BUG() should incorporate an empty a
do...while statement to avoid compilation weirdness.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/asm-generic/bug.h

@@ -88,7 +88,7 @@ extern void warn_slowpath(const char *file, const int line,
 
 #else /* !CONFIG_BUG */
 #ifndef HAVE_ARCH_BUG
-#define BUG()
+#define BUG() do {} while(0)
 #endif
 
 #ifndef HAVE_ARCH_BUG_ON