irda-usb: treat firmware data as const

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

drivers/net/irda/irda-usb.c

@@ -1024,7 +1024,7 @@ static int irda_usb_is_receiving(struct irda_usb_cb *self)
  *   Upload firmware code to SigmaTel 421X IRDA-USB dongle
  */
 static int stir421x_fw_upload(struct irda_usb_cb *self,
-			     unsigned char *patch,
+			     const unsigned char *patch,
 			     const unsigned int patch_len)
 {
         int ret = -ENOMEM;
@@ -1077,7 +1077,7 @@ static int stir421x_patch_device(struct irda_usb_cb *self)
 	int ret;
 	char stir421x_fw_name[11];
 	const struct firmware *fw;
-        unsigned char *fw_version_ptr; /* pointer to version string */
+	const unsigned char *fw_version_ptr; /* pointer to version string */
 	unsigned long fw_version = 0;
 
         /*