[PATCH v2] trace: use WARN instead of printk and WARN_ON

[Guo Zhengkui]

Use `WARN(cond, ...)` instead of `if (cond)` + `printk(...)` +
`WARN_ON(1)`.

Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Qing Wang <wangqing@xxxxxxxx>
Signed-off-by: Guo Zhengkui <guozhengkui@xxxxxxxx>
---
v1 -> v2: Put WARN in the condition according to Steven's suggestion.

 kernel/trace/trace_output.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 8aa493d25c73..d89e3f7e26eb 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -778,9 +778,8 @@ int register_trace_event(struct trace_event *event)
 
 		list_add_tail(&event->list, list);
 
-	} else if (event->type > __TRACE_LAST_TYPE) {
-		printk(KERN_WARNING "Need to add type to trace.h\n");
-		WARN_ON(1);
+	} else if (WARN(event->type > __TRACE_LAST_TYPE,
+			"Need to add type to trace.h")) {
 		goto out;
 	} else {
 		/* Is this event already used */
@@ -1571,13 +1570,8 @@ __init static int init_events(void)
 
 	for (i = 0; events[i]; i++) {
 		event = events[i];
-
 		ret = register_trace_event(event);
-		if (!ret) {
-			printk(KERN_WARNING "event %d failed to register\n",
-			       event->type);
-			WARN_ON_ONCE(1);
-		}
+		WARN_ONCE(!ret, "event %d failed to register", event->type);
 	}
 
 	return 0;
-- 
2.20.1