rt2x00: treat firmware data as const

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/drivers/net/wireless/rt2x00/rt61pci.c b/drivers/net/wireless/rt2x00/rt61pci.c
index 14bc7b2..bb78de5 100644
--- a/drivers/net/wireless/rt2x00/rt61pci.c
+++ b/drivers/net/wireless/rt2x00/rt61pci.c
@@ -915,7 +915,7 @@
 	return fw_name;
 }
 
-static u16 rt61pci_get_firmware_crc(void *data, const size_t len)
+static u16 rt61pci_get_firmware_crc(const void *data, const size_t len)
 {
 	u16 crc;
 
@@ -932,7 +932,7 @@
 	return crc;
 }
 
-static int rt61pci_load_firmware(struct rt2x00_dev *rt2x00dev, void *data,
+static int rt61pci_load_firmware(struct rt2x00_dev *rt2x00dev, const void *data,
 				 const size_t len)
 {
 	int i;