i2c: Make i2c_del_driver a void function

Make i2c_del_driver a void function, like all other driver removal
functions. It always returned 0 even when errors occured, and nobody
ever actually checked the return value anyway. And we cannot fail
a module removal anyway.

Signed-off-by: Jean Delvare <khali@linux-fr.org>

drivers/macintosh/therm_windtunnel.c

@@ -459,7 +459,8 @@ therm_of_probe( struct of_device *dev, const struct of_device_id *match )
 static int
 therm_of_remove( struct of_device *dev )
 {
-	return i2c_del_driver( &g4fan_driver );
+	i2c_del_driver( &g4fan_driver );
+	return 0;
 }
 
 static struct of_device_id therm_of_match[] = {{