tty: Fix bogus "callbacks suppressed" messages

On the current git tree one sees messages such as:
 tty_init_dev: 24 callbacks suppressed
 tty_init_dev: 3 callbacks suppressed

To fix this we need to look at condition before calling __ratelimit in
the WARN_RATELIMIT macro. While at it remove the superfluous
__WARN_RATELIMIT macros.

Original patch is from Joe Perches and Jiri Slaby.

Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Acked-and-tested-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/ratelimit.h

@@ -46,36 +46,27 @@ extern int ___ratelimit(struct ratelimit_state *rs, const char *func);
 #define WARN_ON_RATELIMIT(condition, state)			\
 		WARN_ON((condition) && __ratelimit(state))
 
-#define __WARN_RATELIMIT(condition, state, format...)		\
-({								\
-	int rtn = 0;						\
-	if (unlikely(__ratelimit(state)))			\
-		rtn = WARN(condition, format);			\
-	rtn;							\
-})
-
-#define WARN_RATELIMIT(condition, format...)			\
+#define WARN_RATELIMIT(condition, format, ...)			\
 ({								\
 	static DEFINE_RATELIMIT_STATE(_rs,			\
 				      DEFAULT_RATELIMIT_INTERVAL,	\
 				      DEFAULT_RATELIMIT_BURST);	\
-	__WARN_RATELIMIT(condition, &_rs, format);		\
+	int rtn = !!(condition);				\
+								\
+	if (unlikely(rtn && __ratelimit(&_rs)))			\
+		WARN(rtn, format, ##__VA_ARGS__);		\
+								\
+	rtn;							\
 })
 
 #else
 
 #define WARN_ON_RATELIMIT(condition, state)			\
 	WARN_ON(condition)
 
-#define __WARN_RATELIMIT(condition, state, format...)		\
-({								\
-	int rtn = WARN(condition, format);			\
-	rtn;							\
-})
-
-#define WARN_RATELIMIT(condition, format...)			\
+#define WARN_RATELIMIT(condition, format, ...)			\
 ({								\
-	int rtn = WARN(condition, format);			\
+	int rtn = WARN(condition, format, ##__VA_ARGS__);	\
 	rtn;							\
 })