iio: adc: intel_mrfld_adc: Allocating too much data in probe()

This probe function is passing the wrong size to devm_iio_device_alloc().
It is supposed to be the size of the private data.  Fortunately,
sizeof(*indio_dev) is larger than sizeof(struct mrfld_adc) so it doesn't
cause a runtime problem.

Fixes: a7118662 ("iio: adc: intel_mrfld_adc: Add Basin Cove ADC driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/intel_mrfld_adc.c

@@ -185,7 +185,7 @@ static int mrfld_adc_probe(struct platform_device *pdev)
 	int irq;
 	int ret;
 
-	indio_dev = devm_iio_device_alloc(dev, sizeof(*indio_dev));
+	indio_dev = devm_iio_device_alloc(dev, sizeof(struct mrfld_adc));
 	if (!indio_dev)
 		return -ENOMEM;