platform/chrome: Use proper protocol transfer function

pkt_xfer should be used for protocol v3, and cmd_xfer otherwise. We had
one instance of these functions correct, but not the second, fall-back
case. We use the fall-back only when the first command returns an
IN_PROGRESS status, which is only used on some EC firmwares where we
don't want to constantly poll the bus, but instead back off and
sleep/retry for a little while.

Fixes: 2c7589af3c4d ("mfd: cros_ec: add proto v3 skeleton")
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

drivers/platform/chrome/cros_ec_proto.c

@@ -60,12 +60,14 @@ static int send_command(struct cros_ec_device *ec_dev,
 			struct cros_ec_command *msg)
 {
 	int ret;
+	int (*xfer_fxn)(struct cros_ec_device *ec, struct cros_ec_command *msg);
 
 	if (ec_dev->proto_version > 2)
-		ret = ec_dev->pkt_xfer(ec_dev, msg);
+		xfer_fxn = ec_dev->pkt_xfer;
 	else
-		ret = ec_dev->cmd_xfer(ec_dev, msg);
+		xfer_fxn = ec_dev->cmd_xfer;
 
+	ret = (*xfer_fxn)(ec_dev, msg);
 	if (msg->result == EC_RES_IN_PROGRESS) {
 		int i;
 		struct cros_ec_command *status_msg;
@@ -88,7 +90,7 @@ static int send_command(struct cros_ec_device *ec_dev,
 		for (i = 0; i < EC_COMMAND_RETRIES; i++) {
 			usleep_range(10000, 11000);
 
-			ret = ec_dev->cmd_xfer(ec_dev, status_msg);
+			ret = (*xfer_fxn)(ec_dev, status_msg);
 			if (ret < 0)
 				break;