Fix a const pointer error in the Conexant cx23418 MPEG encoder driver

Fix a const pointer to non-const pointer assignment error in the Conexant
cx23418 MPEG encoder driver.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/media/video/cx18/cx18-av-firmware.c

@@ -29,7 +29,7 @@ int cx18_av_loadfw(struct cx18 *cx)
 	const struct firmware *fw = NULL;
 	u32 size;
 	u32 v;
-	u8 *ptr;
+	const u8 *ptr;
 	int i;
 
 	if (request_firmware(&fw, FWFILE, &cx->dev->dev) != 0) {