iio: dac: ad5791: fix backported MODULE_IMPORT_NS

Fix compile error due to backported MODULE_IMPORT_NS(). The 6.6 kernel
expects the argument to this to not be quoted while newer kernels
expect it to be quoted.

When we backported commit 192b669 ("iio: dac: ad5791: Add offload
support") we missed adapting this difference.

Signed-off-by: David Lechner <dlechner@baylibre.com>

Author: dlech

drivers/iio/dac/ad5791.c

@@ -614,4 +614,4 @@ module_spi_driver(ad5791_driver);
 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 MODULE_DESCRIPTION("Analog Devices AD5760/AD5780/AD5781/AD5790/AD5791 DAC");
 MODULE_LICENSE("GPL v2");
-MODULE_IMPORT_NS("IIO_DMAENGINE_BUFFER");
+MODULE_IMPORT_NS(IIO_DMAENGINE_BUFFER);