greybus: gb-audio: fix build warning

sizeof wants %zu when on a 64bit build, so change the dev_err() call to
remove a build warning in the audio.c file.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Acked-by: John Stultz <john.stultz@linaro.org>

drivers/staging/greybus/audio.c

@@ -307,7 +307,7 @@ static int gb_i2s_mgmt_report_event_recv(u8 type, struct gb_operation *op)
 	}
 
 	if (op->request->payload_size < sizeof(*req)) {
-		dev_err(&connection->dev, "Short request received: %d, %d\n",
+		dev_err(&connection->dev, "Short request received: %zu, %zu\n",
 			op->request->payload_size, sizeof(*req));
 		return -EINVAL;
 	}