rcu: Avoid sparse warnings in rcu_nocb_wake trace event

The event-tracing macros do not like bool tracing arguments, so this
commit makes them be of type char.  This change has the knock-on effect
of making it illegal to pass a pointer into one of these arguments, so
also change rcutiny's first call to trace_rcu_batch_end() to convert
from pointer to boolean, prefixing with "!!".

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

include/trace/events/rcu.h

@@ -591,17 +591,17 @@ TRACE_EVENT(rcu_invoke_kfree_callback,
 TRACE_EVENT(rcu_batch_end,
 
 	TP_PROTO(const char *rcuname, int callbacks_invoked,
-		 bool cb, bool nr, bool iit, bool risk),
+		 char cb, char nr, char iit, char risk),
 
 	TP_ARGS(rcuname, callbacks_invoked, cb, nr, iit, risk),
 
 	TP_STRUCT__entry(
 		__field(const char *, rcuname)
 		__field(int, callbacks_invoked)
-		__field(bool, cb)
-		__field(bool, nr)
-		__field(bool, iit)
-		__field(bool, risk)
+		__field(char, cb)
+		__field(char, nr)
+		__field(char, iit)
+		__field(char, risk)
 	),
 
 	TP_fast_assign(

kernel/rcutiny.c

@@ -273,7 +273,7 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
 	if (&rcp->rcucblist == rcp->donetail) {
 		RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, 0, -1));
 		RCU_TRACE(trace_rcu_batch_end(rcp->name, 0,
-					      ACCESS_ONCE(rcp->rcucblist),
+					      !!ACCESS_ONCE(rcp->rcucblist),
 					      need_resched(),
 					      is_idle_task(current),
 					      false));