staging:iio: Use module_spi_driver to register SPI driver

Use the newly introduced module_spi_driver macro for registering SPI drivers.
This allows us to remove a few lines of boilerplate code.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/iio/dac/ad5791.c b/drivers/staging/iio/dac/ad5791.c
index 6fbca8d..4a80fd8 100644
--- a/drivers/staging/iio/dac/ad5791.c
+++ b/drivers/staging/iio/dac/ad5791.c
@@ -410,18 +410,7 @@
 	.remove = __devexit_p(ad5791_remove),
 	.id_table = ad5791_id,
 };
-
-static __init int ad5791_spi_init(void)
-{
-	return spi_register_driver(&ad5791_driver);
-}
-module_init(ad5791_spi_init);
-
-static __exit void ad5791_spi_exit(void)
-{
-	spi_unregister_driver(&ad5791_driver);
-}
-module_exit(ad5791_spi_exit);
+module_spi_driver(ad5791_driver);
 
 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 MODULE_DESCRIPTION("Analog Devices AD5760/AD5780/AD5781/AD5791 DAC");