iio: adc: rockchip_saradc: fix missing clk_disable_unprepare() on error in rockchip_s...

iio: adc: rockchip_saradc: fix missing clk_disable_unprepare() on error in rockchip_saradc_resume

Fix the missing clk_disable_unprepare() of info->pclk
before return from rockchip_saradc_resume in the error
handling case when fails to prepare and enable info->clk.

Suggested-by: Robin Murphy <robin.murphy@arm.com>
Fixes: 44d6f2ef94f9 ("iio: adc: add driver for Rockchip saradc")
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20201103120743.110662-1-miaoqinglang@huawei.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>