ring-buffer: Fix memleak in ring_buffer_free()

I noticed oprofile memleaked in linux-2.6 current tree,
and tracked this ring-buffer leak.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
LKML-Reference: <4A7C06B9.2090302@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index d4d3580..a330513 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -735,6 +735,7 @@
 
 	put_online_cpus();
 
+	kfree(buffer->buffers);
 	free_cpumask_var(buffer->cpumask);
 
 	kfree(buffer);