rcu: trace fix possible mem-leak

In the initialization of the RCU trace module, if
rcupreempt_debugfs_init() fails, we never free the the trace buffer.

This patch frees the trace buffer in case the debugfs fails.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Reviewed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/rcupreempt_trace.c

@@ -308,11 +308,16 @@ out:
 
 static int __init rcupreempt_trace_init(void)
 {
+	int ret;
+
 	mutex_init(&rcupreempt_trace_mutex);
 	rcupreempt_trace_buf = kmalloc(RCUPREEMPT_TRACE_BUF_SIZE, GFP_KERNEL);
 	if (!rcupreempt_trace_buf)
 		return 1;
-	return rcupreempt_debugfs_init();
+	ret = rcupreempt_debugfs_init();
+	if (ret)
+		kfree(rcupreempt_trace_buf);
+	return ret;
 }
 
 static void __exit rcupreempt_trace_cleanup(void)