Driver core: Constify struct sysfs_ops in struct kobj_type

Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <[email protected]>
Acked-by: David Teigland <[email protected]>
Acked-by: Matt Domsch <[email protected]>
Acked-by: Maciej Sosnowski <[email protected]>
Acked-by: Hans J. Koch <[email protected]>
Acked-by: Pekka Enberg <[email protected]>
Acked-by: Jens Axboe <[email protected]>
Acked-by: Stephen Hemminger <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Documentation/kobject.txt

@@ -266,7 +266,7 @@ kobj_type:
 
     struct kobj_type {
 	    void (*release)(struct kobject *);
-	    struct sysfs_ops	*sysfs_ops;
+	    const struct sysfs_ops *sysfs_ops;
 	    struct attribute	**default_attrs;
     };