mfd: ocelot-spi: Use spi_sync_transfer()

Use spi_sync_transfer() instead of hand-writing it.

It is less verbose.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Colin Foster <colin.foster@in-advantage.com>
Tested-by: Colin Foster <colin.foster@in-advantage.com>
Link: https://lore.kernel.org/r/7af920eb686b719cb7eb39c832e3ad414e0e1e1a.1712258667.git.christophe.jaillet@wanadoo.frSigned-off-by: Lee Jones <lee@kernel.org>

drivers/mfd/ocelot-spi.c

@@ -145,7 +145,6 @@ static int ocelot_spi_regmap_bus_read(void *context, const void *reg, size_t reg
 	struct device *dev = context;
 	struct ocelot_ddata *ddata;
 	struct spi_device *spi;
-	struct spi_message msg;
 	unsigned int index = 0;
 
 	ddata = dev_get_drvdata(dev);
@@ -166,9 +165,7 @@ static int ocelot_spi_regmap_bus_read(void *context, const void *reg, size_t reg
 	xfers[index].len = val_size;
 	index++;
 
-	spi_message_init_with_transfers(&msg, xfers, index);
-
-	return spi_sync(spi, &msg);
+	return spi_sync_transfer(spi, xfers, index);
 }
 
 static int ocelot_spi_regmap_bus_write(void *context, const void *data, size_t count)