usb/kaweth: use GFP_ATOMIC under spin_lock in usb_start_wait_urb()

Commit e4c7f259 ("USB: kaweth.c: use GFP_ATOMIC under spin_lock")
makes sure that kaweth_internal_control_msg() allocates memory with GFP_ATOMIC,
but kaweth_internal_control_msg() also calls usb_start_wait_urb()
that still allocates memory with GFP_NOIO.

The patch fixes usb_start_wait_urb() as well.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: David S. Miller <davem@davemloft.net>