iio: imu: st_lsm6dsx: remove set but not used variables 'acc_sensor' and 'gyro_sensor'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c: In function 'st_lsm6dsx_read_tagged_fifo':
drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c:520:41: warning:
 variable 'gyro_sensor' set but not used [-Wunused-but-set-variable]

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c:520:28: warning:
 variable 'acc_sensor' set but not used [-Wunused-but-set-variable]

They are not used since commit 14c7c6e1a8 ("iio: imu: st_lsm6dsx: add
st_lsm6dsx_push_tagged_data routine")

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c

@@ -517,7 +517,6 @@ int st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw *hw)
 {
 	u16 pattern_len = hw->sip * ST_LSM6DSX_TAGGED_SAMPLE_SIZE;
 	u16 fifo_len, fifo_diff_mask;
-	struct st_lsm6dsx_sensor *acc_sensor, *gyro_sensor;
 	u8 iio_buff[ST_LSM6DSX_IIO_BUFF_SIZE], tag;
 	bool reset_ts = false;
 	int i, err, read_len;
@@ -539,9 +538,6 @@ int st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw *hw)
 	if (!fifo_len)
 		return 0;
 
-	acc_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
-	gyro_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_GYRO]);
-
 	for (read_len = 0; read_len < fifo_len; read_len += pattern_len) {
 		err = st_lsm6dsx_read_block(hw,
 					    ST_LSM6DSX_REG_FIFO_OUT_TAG_ADDR,