[PATCH] tty buffering: comment out debug code

Comment out debug code in tty receive buffering.  For performance reasons
(I'll keep it enabled in -mm).

Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>