iio: accel: adxl345: Convert to use dev_err_probe()

It's fine to call dev_err_probe() in ->probe() when error code is known.
Convert the driver to use dev_err_probe().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Link: https://lore.kernel.org/r/20220222090009.2060-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>