iio: pressure: dps310: consistently check return value of `regmap_read`

Align the check of return values `regmap_read` so that it's consistent
across this driver code.

Signed-off-by: Thomas Haemmerle <thomas.haemmerle@leica-geosystems.com>
Link: https://lore.kernel.org/r/20240415105030.1161770-4-thomas.haemmerle@leica-geosystems.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>