spi/fsl-espi: Correct the maximum transaction length

The maximum length during one transcation is 64KiB.
Signed-off-by: Hou Zhiqiang <B48286@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-fsl-espi.c

@@ -84,7 +84,7 @@ struct fsl_espi_transfer {
 /* SPCOM register values */
 #define SPCOM_CS(x)		((x) << 30)
 #define SPCOM_TRANLEN(x)	((x) << 0)
-#define	SPCOM_TRANLEN_MAX	0xFFFF	/* Max transaction length */
+#define	SPCOM_TRANLEN_MAX	0x10000	/* Max transaction length */
 
 #define AUTOSUSPEND_TIMEOUT 2000
 
@@ -233,7 +233,7 @@ static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
 	reinit_completion(&mpc8xxx_spi->done);
 
 	/* Set SPCOM[CS] and SPCOM[TRANLEN] field */
-	if ((t->len - 1) > SPCOM_TRANLEN_MAX) {
+	if (t->len > SPCOM_TRANLEN_MAX) {
 		dev_err(mpc8xxx_spi->dev, "Transaction length (%d)"
 				" beyond the SPCOM[TRANLEN] field\n", t->len);
 		return -EINVAL;