tracing: wrap arguments with PARAMS

Peter Zijlstra warned that TPPROTO and TPARGS might become something
other than a simple copy of itself. To prevent this from having
side effects in the TRACE_FORMAT macro in tracepoint.h, we add a
PARAMS() macro to be defined as just a wrapper.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

include/linux/tracepoint.h

@@ -153,7 +153,8 @@ static inline void tracepoint_synchronize_unregister(void)
 	synchronize_sched();
 }
 
+#define PARAMS(args...) args
 #define TRACE_FORMAT(name, proto, args, fmt)		\
-	DECLARE_TRACE(name, TPPROTO(proto), TPARGS(args))
+	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
 
 #endif