[PATCH] Fix warnings for WARN_ON if CONFIG_BUG is disabled

In most cases the return value of WARN_ON() is ignored.  If the generic
definition for the !CONFIG_BUG case is used this will result in a warning:

  CC      kernel/sched.o
In file included from include/linux/bio.h:25,
                 from include/linux/blkdev.h:14,
                 from kernel/sched.c:39:
include/linux/ioprio.h: In function ‘task_ioprio’:
include/linux/ioprio.h:50: warning: statement with no effect
kernel/sched.c: In function ‘context_switch’:
kernel/sched.c:1834: warning: statement with no effect
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-generic/bug.h

@@ -37,7 +37,10 @@
 #endif
 
 #ifndef HAVE_ARCH_WARN_ON
-#define WARN_ON(condition) unlikely((condition))
+#define WARN_ON(condition) ({						\
+	typeof(condition) __ret_warn_on = (condition);			\
+	unlikely(__ret_warn_on);					\
+})
 #endif
 #endif