w1: add __init/__exit macros to w1.c

Trivial patch which adds the __init/__exit macros to the module_init/
module_exit functions of

drivers/w1/w1.c
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/w1/w1.c

@@ -986,7 +986,7 @@ int w1_process(void *data)
 	return 0;
 }
 
-static int w1_init(void)
+static int __init w1_init(void)
 {
 	int retval;
 
@@ -1034,7 +1034,7 @@ static int w1_init(void)
 	return retval;
 }
 
-static void w1_fini(void)
+static void __exit w1_fini(void)
 {
 	struct w1_master *dev;