iio: adis16475: do not directly change spi 'max_speed_hz'

With commit 3ba10e37371d ("iio: adis: add burst_max_speed_hz variable"), we
just need to define 'burst_max_speed_hz' and the adis core will take
care of setting up the spi transfers for burst mode. Hence, we fix
a potential race with the spi core where we could be left with an
invalid 'max_speed_hz'.
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Fixes: fff7352b ("iio: imu: Add support for adis16475")
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210427085454.30616-6-nuno.sa@analog.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/adis16475.c

@@ -645,7 +645,8 @@ static int adis16475_enable_irq(struct adis *adis, bool enable)
 	.timeouts = (_timeouts),					\
 	.burst_reg_cmd = ADIS16475_REG_GLOB_CMD,			\
 	.burst_len = ADIS16475_BURST_MAX_DATA,				\
-	.burst_max_len = ADIS16475_BURST32_MAX_DATA			\
+	.burst_max_len = ADIS16475_BURST32_MAX_DATA,			\
+	.burst_max_speed_hz = ADIS16475_BURST_MAX_SPEED			\
 }
 
 static const struct adis16475_sync adis16475_sync_mode[] = {
@@ -1062,15 +1063,11 @@ static irqreturn_t adis16475_trigger_handler(int irq, void *p)
 	bool valid;
 	/* offset until the first element after gyro and accel */
 	const u8 offset = st->burst32 ? 13 : 7;
-	const u32 cached_spi_speed_hz = adis->spi->max_speed_hz;
-
-	adis->spi->max_speed_hz = ADIS16475_BURST_MAX_SPEED;
 
 	ret = spi_sync(adis->spi, &adis->msg);
 	if (ret)
 		goto check_burst32;
 
-	adis->spi->max_speed_hz = cached_spi_speed_hz;
 	buffer = adis->buffer;
 
 	crc = be16_to_cpu(buffer[offset + 2]);