tracing: Remove unnecessary NULL assignment

Remove unnecessary NULL assignment int create_new_subsystem().

Link: https://lkml.kernel.org/r/20221123065124.3982439-1-bobo.shaobowang@huawei.comSigned-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

kernel/trace/trace_events.c

@@ -2261,8 +2261,6 @@ create_new_subsystem(const char *name)
 	if (!system->name)
 		goto out_free;
 
-	system->filter = NULL;
-
 	system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
 	if (!system->filter)
 		goto out_free;