staging:iio: use spi->irq valid rather than querying available modes

Given these drivers only try to add the trigger if a valid
irq is present it is clearer to check the same condition when
deciding whether to remove it on a later trigger.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/iio/imu/adis16400_core.c

@@ -1172,7 +1172,7 @@ static int __devinit adis16400_probe(struct spi_device *spi)
 	return 0;
 
 error_remove_trigger:
-	if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
+	if (spi->irq)
 		adis16400_remove_trigger(indio_dev);
 error_uninitialize_ring:
 	iio_buffer_unregister(indio_dev);

drivers/staging/iio/meter/ade7758_core.c

@@ -800,7 +800,7 @@ static int __devinit ade7758_probe(struct spi_device *spi)
 	return 0;
 
 error_remove_trigger:
-	if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
+	if (spi->irq)
 		ade7758_remove_trigger(indio_dev);
 error_uninitialize_ring:
 	ade7758_uninitialize_ring(indio_dev);