hwmon: convert drivers/hwmon/* to use module_i2c_driver()

This patch converts the drivers in drivers/hwmon/* to use the
module_i2c_driver() macro which makes the code smaller and a bit simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Corentin Labbe <corentin.labbe@geomatys.fr>
Cc: Dirk Eibach <eibach@gdsys.de>
Cc: "Mark M. Hoffman" <mhoffman@lightlink.com>
Cc: Steve Glendinning <steve.glendinning@smsc.com>
Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Guillaume Ligneul <guillaume.ligneul@gmail.com>
Cc: David George <david.george@ska.ac.za>
Cc: "Hans J. Koch" <hjk@hansjkoch.de>
Cc: Marc Hulsman <m.hulsman@tudelft.nl>
Cc: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
diff --git a/drivers/hwmon/sht21.c b/drivers/hwmon/sht21.c
index 1539878..6c2dede 100644
--- a/drivers/hwmon/sht21.c
+++ b/drivers/hwmon/sht21.c
@@ -261,28 +261,7 @@
 	.id_table    = sht21_id,
 };
 
-/**
- * sht21_init() - initialize driver
- *
- * Called when kernel is booted or module is inserted.
- * Returns 0 on success.
- */
-static int __init sht21_init(void)
-{
-	return i2c_add_driver(&sht21_driver);
-}
-module_init(sht21_init);
-
-/**
- * sht21_init() - clean up driver
- *
- * Called when module is removed.
- */
-static void __exit sht21_exit(void)
-{
-	i2c_del_driver(&sht21_driver);
-}
-module_exit(sht21_exit);
+module_i2c_driver(sht21_driver);
 
 MODULE_AUTHOR("Urs Fleisch <urs.fleisch@sensirion.com>");
 MODULE_DESCRIPTION("Sensirion SHT21 humidity and temperature sensor driver");