rt2x00: treat firmware data as const

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/drivers/net/wireless/rt2x00/rt73usb.c b/drivers/net/wireless/rt2x00/rt73usb.c
index 83cc014..d5a6c21 100644
--- a/drivers/net/wireless/rt2x00/rt73usb.c
+++ b/drivers/net/wireless/rt2x00/rt73usb.c
@@ -856,7 +856,7 @@
 	return FIRMWARE_RT2571;
 }
 
-static u16 rt73usb_get_firmware_crc(void *data, const size_t len)
+static u16 rt73usb_get_firmware_crc(const void *data, const size_t len)
 {
 	u16 crc;
 
@@ -873,13 +873,13 @@
 	return crc;
 }
 
-static int rt73usb_load_firmware(struct rt2x00_dev *rt2x00dev, void *data,
+static int rt73usb_load_firmware(struct rt2x00_dev *rt2x00dev, const void *data,
 				 const size_t len)
 {
 	unsigned int i;
 	int status;
 	u32 reg;
-	char *ptr = data;
+	const char *ptr = data;
 	char *cache;
 	int buflen;
 	int timeout;