iio: tmag5273: Fix runtime PM leak on measurement error

iio: tmag5273: Fix runtime PM leak on measurement error

The tmag5273 gets a runtime PM reference before reading a measurement and
releases it when done. But if the measurement fails the tmag5273_read_raw()
function exits before releasing the reference.

Make sure that this error path also releases the runtime PM reference.

Fixes: 866a1389174b ("iio: magnetometer: add ti tmag5273 driver")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Gerald Loacker <gerald.loacker@wolfvision.net>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20230414013752.498767-1-lars@metafoo.de
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>