iio: chemical: scd30: Use guard(mutex) to allow early returns

iio: chemical: scd30: Use guard(mutex) to allow early returns

Auto cleanup based release of the lock allows for simpler code flow in a
few functions with large multiplexing style switch statements and no
common operations following the switch.

Suggested-by: David Lechner <dlechner@baylibre.com>
Cc: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250209180624.701140-3-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>