iio: adc: ade9000: fix wrong return type in streaming push

iio: adc: ade9000: fix wrong return type in streaming push

The else branch of ade9000_iio_push_streaming() incorrectly returns
IRQ_HANDLED on regmap_write failure. This function returns int (0 on
success, negative errno on failure), so IRQ_HANDLED (1) would be
misinterpreted as a non-error by callers.

Return ret instead, consistent with every other error path in the
function.

Fixes: 81de7b4619fc ("iio: adc: add ade9000 support")
Signed-off-by: Giorgi Tchankvetadze <giorgitchankvetadze1997@gmail.com>
Reviewed-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>