[PATCH 1/2] tracing: Use str_has_prefix() in synth_event_create()

[Tom Zanussi]

From: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>

Since we now have a str_has_prefix() that returns the length, we can
use that instead of explicitly calculating it.

Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
Cc: Joe Perches <joe@xxxxxxxxxxx>
---
 kernel/trace/trace_events_hist.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 449d90cfa151..c4a667503bf0 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1200,8 +1200,8 @@ static int synth_event_create(int argc, const char **argv)
 
 	/* This interface accepts group name prefix */
 	if (strchr(name, '/')) {
-		len = sizeof(SYNTH_SYSTEM "/") - 1;
-		if (strncmp(name, SYNTH_SYSTEM "/", len))
+		len = str_has_prefix(name, SYNTH_SYSTEM "/");
+		if (len == 0)
 			return -EINVAL;
 		name += len;
 	}
-- 
2.14.1