iio: light: bh1780: fix PM runtime leak on error path

iio: light: bh1780: fix PM runtime leak on error path

Move pm_runtime_put_autosuspend() before the error check to ensure
the PM runtime reference count is always decremented after
pm_runtime_get_sync(), regardless of whether the read operation
succeeds or fails.

Fixes: 1f0477f18306 ("iio: light: new driver for the ROHM BH1780")
Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>