Restructure usb_sg_cancel() so we don't have to disable interrupts
while cancelling the URBs.
Suggested-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NDavid Mosberger <davidm@egauge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>