[media] pctv452e: don't call BUG_ON() on non-fatal error

There are some conditions on this driver that are tested with
BUG_ON() with are not serious enough to hang a machine.

So, just return an error if this happens.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/dvb-usb/pctv452e.c

@@ -109,9 +109,10 @@ static int tt3650_ci_msg(struct dvb_usb_device *d, u8 cmd, u8 *data,
 	unsigned int rlen;
 	int ret;
 
-	BUG_ON(NULL == data && 0 != (write_len | read_len));
-	BUG_ON(write_len > 64 - 4);
-	BUG_ON(read_len > 64 - 4);
+	if (!data || (write_len > 64 - 4) || (read_len > 64 - 4)) {
+		err("%s: transfer data invalid", __func__);
+		return -EIO;
+	};
 
 	mutex_lock(&state->ca_mutex);
 	id = state->c++;