tracing: Fix failure path in ftrace_regex_open()

Don't forget to free trace_parser if seq_open() returned failure.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4AB86694.4040803@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kernel/trace/ftrace.c

@@ -1621,8 +1621,10 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
 		if (!ret) {
 			struct seq_file *m = file->private_data;
 			m->private = iter;
-		} else
+		} else {
+			trace_parser_put(&iter->parser);
 			kfree(iter);
+		}
 	} else
 		file->private_data = iter;
 	mutex_unlock(&ftrace_regex_lock);