iio: temperature: ltc2983: convert to dev_err_probe()

Use dev_err_probe() (and variants) in the probe() path. While at it, made
some simple improvements:
 * Explicitly included the err.h and errno.h headers;
 * Removed some unnecessary line breaks;
 * Removed a redundant 'else';
 * Added some missing \n to prink.
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://patch.msgid.link/20240606-dev-add_dev_errp_probe-v3-2-51bb229edd79@analog.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>