usb: usbtest: reduce stack usage in test_queue

usb: usbtest: reduce stack usage in test_queue

Fix the warning: [-Werror=-Wframe-larger-than=]

drivers/usb/misc/usbtest.c: In function 'test_queue':
drivers/usb/misc/usbtest.c:2148:1:
warning: the frame size of 1232 bytes is larger than 1024 bytes

Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Link: https://lore.kernel.org/r/ffa85702-86ab-48d7-4da2-2efcc94b05d3@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>