Documentation: Add CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF case

This patch add a case with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/kmemleak.txt b/Documentation/kmemleak.txt
index f4f033c..45e777f 100644
--- a/Documentation/kmemleak.txt
+++ b/Documentation/kmemleak.txt
@@ -62,6 +62,10 @@
 these actions are stored in an early log buffer. The size of this buffer
 is configured via the CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE option.
 
+If CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF are enabled, the kmemleak is
+disabled by default. Passing "kmemleak=on" on the kernel command
+line enables the function. 
+
 Basic Algorithm
 ---------------