iio: adc: vf610: fix simple_return.cocci warnings

drivers/iio/adc/vf610_adc.c:766:1-4: WARNING: end returns can be simpified and declaration on line 755 can be dropped

 Simplify a trivial if-return sequence.  Possibly combine with a
 preceding function call.

Generated by: scripts/coccinelle/misc/simple_return.cocci

CC: Sanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/vf610_adc.c

@@ -752,7 +752,7 @@ static int vf610_adc_buffer_predisable(struct iio_dev *indio_dev)
 {
 	struct vf610_adc *info = iio_priv(indio_dev);
 	unsigned int hc_cfg = 0;
-	int val, ret;
+	int val;
 
 	val = readl(info->regs + VF610_REG_ADC_GC);
 	val &= ~VF610_ADC_ADCON;
@@ -763,11 +763,7 @@ static int vf610_adc_buffer_predisable(struct iio_dev *indio_dev)
 
 	writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);
 
-	ret = iio_triggered_buffer_predisable(indio_dev);
-	if (ret)
-		return ret;
-
-	return 0;
+	return iio_triggered_buffer_predisable(indio_dev);
 }
 
 static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {