staging: improved comment style in ft1000_debug.c

Replaced C99 style comments with C89 in
"/drivers/staging/ft1000/ft1000-usb/ft1000_debug.c".

Signed-off-by: Katja Collier <katjacollier@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>