spi: xcomm: Remove duplicate code to set default bits_per_word and max speed

In the implementation of __spi_validate(), spi core will set transfer
bits_per_word and max speed as spi device default if it is not set for
this transfer. So we can remove the same logic in spi_xcomm_setup_transfer().
Also remove a redundant code to initialize is_first variable.

Signed-off-by: Axel Lin <[e-mail]>
Acked-by: Lars-Peter Clausen <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/spi/spi-xcomm.c

···
 static int spi_xcomm_setup_transfer(struct spi_xcomm *spi_xcomm,
 	struct spi_device *spi, struct spi_transfer *t, unsigned int *settings)
 {
-	unsigned int speed;
-
 	if (t->len > 62)
 		return -EINVAL;
 
-	speed = t->speed_hz ? t->speed_hz : spi->max_speed_hz;
+	if (t->speed_hz != spi_xcomm->current_speed) {
+		unsigned int divider;
 
-	if (speed != spi_xcomm->current_speed) {
-		unsigned int divider = DIV_ROUND_UP(SPI_XCOMM_CLOCK, speed);
+		divider = DIV_ROUND_UP(SPI_XCOMM_CLOCK, t->speed_hz);
 		if (divider >= 64)
 			*settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_64;
 		else if (divider >= 16)
···
 		else
 			*settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_4;
 
-		spi_xcomm->current_speed = speed;
+		spi_xcomm->current_speed = t->speed_hz;
 	}
 
 	if (spi->mode & SPI_CPOL)
···
 	bool is_first = true;
 	int status = 0;
 	bool is_last;
-
-	is_first = true;
 
 	spi_xcomm_chipselect(spi_xcomm, spi, true);