iio: adc: mxs-lradc: fix the order of two cleanup operations

Smatch reports:
drivers/iio/adc/mxs-lradc-adc.c:766 mxs_lradc_adc_probe() warn:
missing unwind goto?

the order of three init operation:
1.mxs_lradc_adc_trigger_init
2.iio_triggered_buffer_setup
3.mxs_lradc_adc_hw_init

thus, the order of three cleanup operation should be:
1.mxs_lradc_adc_hw_stop
2.iio_triggered_buffer_cleanup
3.mxs_lradc_adc_trigger_remove

we exchange the order of two cleanup operations,
introducing the following differences:
1.if mxs_lradc_adc_trigger_init fails, returns directly;
2.if trigger_init succeeds but iio_triggered_buffer_setup fails,
goto err_trig and remove the trigger.

In addition, we also reorder the unwind that goes on in the
remove() callback to match the new ordering.

Fixes: 6dd112b9

 ("iio: adc: mxs-lradc: Add support for ADC driver")
Signed-off-by: Jiakai Luo <jkluo@hust.edu.cn>
Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
Link: https://lore.kernel.org/r/20230422133407.72908-1-jkluo@hust.edu.cn
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>