USB: f_ncm: ncm_bitrate (speed) is unsigned

[  190.544755] configfs-gadget gadget: notify speed -44967296

This is because 4250000000 - 2**32 is -44967296.

Fixes: 9f6ce42 ("usb: gadget: f_ncm.c added")
Cc: Brooke Basile <brookebasile@gmail.com>
Cc: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: Yauheni Kaliuta <yauheni.kaliuta@nokia.com>
Cc: Linux USB Mailing List <linux-usb@vger.kernel.org>
Acked-By: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210608005344.3762668-1-zenczykowski@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/function/f_ncm.c

@@ -583,7 +583,7 @@ static void ncm_do_notify(struct f_ncm *ncm)
 		data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
 		data[1] = data[0];
 
-		DBG(cdev, "notify speed %d\n", ncm_bitrate(cdev->gadget));
+		DBG(cdev, "notify speed %u\n", ncm_bitrate(cdev->gadget));
 		ncm->notify_state = NCM_NOTIFY_CONNECT;
 		break;
 	}