ath6kl: fix control-message timeout

USB control-message timeouts are specified in milliseconds and should
specifically not vary with CONFIG_HZ.

Fixes: 241b128b ("ath6kl: add back beginnings of USB support")
Cc: stable@vger.kernel.org      # 3.4
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20211025120522.6045-3-johan@kernel.org

drivers/net/wireless/ath/ath6kl/usb.c

@@ -907,7 +907,7 @@ static int ath6kl_usb_submit_ctrl_in(struct ath6kl_usb *ar_usb,
 				 req,
 				 USB_DIR_IN | USB_TYPE_VENDOR |
 				 USB_RECIP_DEVICE, value, index, buf,
-				 size, 2 * HZ);
+				 size, 2000);
 
 	if (ret < 0) {
 		ath6kl_warn("Failed to read usb control message: %d\n", ret);