iio: magnetometer: yas530: Fix return value on error path

iio: magnetometer: yas530: Fix return value on error path

There was a missed return variable assignment in the
default errorpath of the switch statement in yas5xx_probe().
Fix it.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210215153023.47899-1-linus.walleij@linaro.org
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>