zd1201: 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: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/zydas/zd1201.c

@@ -25,7 +25,7 @@
 #include <linux/firmware.h>
 #include "zd1201.h"
 
-static struct usb_device_id zd1201_table[] = {
+static const struct usb_device_id zd1201_table[] = {
 	{USB_DEVICE(0x0586, 0x3400)}, /* Peabird Wireless USB Adapter */
 	{USB_DEVICE(0x0ace, 0x1201)}, /* ZyDAS ZD1201 Wireless USB Adapter */
 	{USB_DEVICE(0x050d, 0x6051)}, /* Belkin F5D6051 usb  adapter */