tracing: Switch to kvfree_rcu() API

Instead of invoking a synchronize_rcu() to free a pointer
after a grace period we can directly make use of new API
that does the same but in more efficient way.

Link: https://lkml.kernel.org/r/20211124110308.2053-10-urezki@gmail.comSigned-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/trace_osnoise.c

@@ -138,8 +138,7 @@ static void osnoise_unregister_instance(struct trace_array *tr)
 	if (!found)
 		return;
 
-	synchronize_rcu();
-	kfree(inst);
+	kvfree_rcu(inst);
 }
 
 /*

kernel/trace/trace_probe.c

@@ -1138,8 +1138,7 @@ int trace_probe_remove_file(struct trace_probe *tp,
 		return -ENOENT;
 
 	list_del_rcu(&link->list);
-	synchronize_rcu();
-	kfree(link);
+	kvfree_rcu(link);
 
 	if (list_empty(&tp->event->files))
 		trace_probe_clear_flag(tp, TP_FLAG_TRACE);