[PATCH] iio: imu: st_lsm6dsx: check st_lsm6dsx_shub_read_output return

[trix]

From: Tom Rix <t...@redhat.com>

clang static analysis reports this represenative problem

st_lsm6dsx_shub.c:540:8: warning: Assigned value is garbage or undefined
        *val = (s16)le16_to_cpu(*((__le16 *)data));
             ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

data is set with

        err = st_lsm6dsx_shub_read(sensor, ch->address, data, len);
        if (err < 0)
                return err;

The problem with st_lsm6dsx_shub_read() is this statement

        err = st_lsm6dsx_shub_read_output(hw, data,
                                          len & ST_LS6DSX_READ_OP_MASK);

The err value is never checked.
So check err.

Fixes: c91c1c844ebd ("iio: imu: st_lsm6dsx: add i2c embedded controller 
support")

Signed-off-by: Tom Rix <t...@redhat.com>
---
 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_shub.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_shub.c 
b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_shub.c
index ed83471dc7dd..8c8d8870ca07 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_shub.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_shub.c
@@ -313,6 +313,8 @@ st_lsm6dsx_shub_read(struct st_lsm6dsx_sensor *sensor, u8 
addr,
 
        err = st_lsm6dsx_shub_read_output(hw, data,
                                          len & ST_LS6DSX_READ_OP_MASK);
+       if (err < 0)
+               return err;
 
        st_lsm6dsx_shub_master_enable(sensor, false);
 
-- 
2.18.1