[PATCH] USB: Converting cdc acm to a ring queue

this patch by David converts the sending queue of the CDC ACM driver
to a queue of URBs. This is needed for quicker devices. Please apply.

Signed-Off-By: Oliver Neukum <oliver@neukum.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

 drivers/usb/class/cdc-acm.c |  229 ++++++++++++++++++++++++++++++--------------
 drivers/usb/class/cdc-acm.h |   33 +++++-
 2 files changed, 185 insertions(+), 77 deletions(-)