iio: adc: ina2xx: Make use of the helper macro kthread_run()

Repalce kthread_create/wake_up_process() with kthread_run()
to simplify the code.

Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Link: https://lore.kernel.org/r/20211021124254.3247-1-caihuoqing@baidu.com


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