HID: adding __init/__exit macros to module init/exit functions

Trivial patch which adds the __init and __exit macros to the module_init /
module_exit functions of several HID drivers from drivers/hid/

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-a4tech.c b/drivers/hid/hid-a4tech.c
index 42ea359..df474c6 100644
--- a/drivers/hid/hid-a4tech.c
+++ b/drivers/hid/hid-a4tech.c
@@ -145,12 +145,12 @@
 	.remove = a4_remove,
 };
 
-static int a4_init(void)
+static int __init a4_init(void)
 {
 	return hid_register_driver(&a4_driver);
 }
 
-static void a4_exit(void)
+static void __exit a4_exit(void)
 {
 	hid_unregister_driver(&a4_driver);
 }