spi: pxa2xx: Fix cs_change management

Fix cs_change management so that it is in line with other spi drivers.

In the spi core api helpers such as spi_bus_lock/unlock and spi_sync_locked
or cs_change field in spi_transfer help to manage chip select from the
device driver.

The driver was setting the chip select to idle if the message queue was
empty despite cs_change or other status field set by spi_bus_lock/unlock
or spi_sync_locked.

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-pxa2xx.c

@@ -570,9 +570,8 @@ static void giveback(struct driver_data *drv_data)
 		/* see if the next and current messages point
 		 * to the same chip
 		 */
-		if (next_msg && next_msg->spi != msg->spi)
-			next_msg = NULL;
-		if (!next_msg || msg->state == ERROR_STATE)
+		if ((next_msg && next_msg->spi != msg->spi) ||
+		    msg->state == ERROR_STATE)
 			cs_deassert(drv_data);
 	}