spi: fsl-espi: simplify fsl_espi_setup_transfer

Simplify fsl_espi_setup_transfer a little.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index a9004fe..b00313b 100644
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -166,12 +166,10 @@
 	mpc8xxx_spi->get_rx = cs->get_rx;
 	mpc8xxx_spi->get_tx = cs->get_tx;
 
-	bits_per_word = bits_per_word - 1;
-
 	/* mask out bits we are going to set */
 	cs->hw_mode &= ~(CSMODE_LEN(0xF) | CSMODE_DIV16 | CSMODE_PM(0xF));
 
-	cs->hw_mode |= CSMODE_LEN(bits_per_word);
+	cs->hw_mode |= CSMODE_LEN(bits_per_word - 1);
 
 	if ((mpc8xxx_spi->spibrg / hz) > 64) {
 		cs->hw_mode |= CSMODE_DIV16;