Input: kbtab - constify usb_device_id

usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/tablet/kbtab.c

@@ -88,7 +88,7 @@ static void kbtab_irq(struct urb *urb)
 			__func__, retval);
 }
 
-static struct usb_device_id kbtab_ids[] = {
+static const struct usb_device_id kbtab_ids[] = {
 	{ USB_DEVICE(USB_VENDOR_ID_KBGEAR, 0x1001), .driver_info = 0 },
 	{ }
 };