hwmon: convert drivers/hwmon/* to use module_spi_driver()

This patch converts the drivers in drivers/hwmon/* to use the
module_spi_driver() macro which makes the code smaller and a bit simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Sonic Zhang <sonic.zhang@analog.com>
Cc: Marc Pignat <marc.pignat@hevs.ch>
Cc: Paul Thomas <pthomas8589@gmail.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Acked-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
diff --git a/drivers/hwmon/ad7314.c b/drivers/hwmon/ad7314.c
index 5d760f3..0e0cfcc 100644
--- a/drivers/hwmon/ad7314.c
+++ b/drivers/hwmon/ad7314.c
@@ -167,17 +167,7 @@
 	.id_table = ad7314_id,
 };
 
-static __init int ad7314_init(void)
-{
-	return spi_register_driver(&ad7314_driver);
-}
-module_init(ad7314_init);
-
-static __exit void ad7314_exit(void)
-{
-	spi_unregister_driver(&ad7314_driver);
-}
-module_exit(ad7314_exit);
+module_spi_driver(ad7314_driver);
 
 MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
 MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital"