[NET] kaweth was forgotten in msec switchover of usb_start_wait_urb

Back in 2.6.12-pre, usb_start_wait_urb was switched over to take
milliseconds instead of jiffies. kaweth.c was never updated to match.

Signed-off-by: Russ Dill <Russ.Dill@asu.edu>
Signed-off-by: Adrian Bunk <bunk@kernel.org>