kobject: remove struct kobj_type from struct kset

We don't need a "default" ktype for a kset.  We should set this
explicitly every time for each kset.  This change is needed so that we
can make ksets dynamic, and cleans up one of the odd, undocumented
assumption that the kset/kobject/ktype model has.

This patch is based on a lot of help from Kay Sievers.

Nasty bug in the block code was found by Dave Young
<hidave.darkstar@gmail.com>

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

fs/ecryptfs/main.c

@@ -734,7 +734,7 @@ static int ecryptfs_init_kmem_caches(void)
 	return 0;
 }
 
-static decl_subsys(ecryptfs, NULL, NULL);
+static decl_subsys(ecryptfs, NULL);
 
 static ssize_t version_show(struct kset *kset, char *buff)
 {
@@ -798,6 +798,7 @@ static int do_sysfs_registration(void)
 {
 	int rc;
 
+	ecryptfs_subsys.kobj.kset = &fs_subsys;
 	rc = subsystem_register(&ecryptfs_subsys);
 	if (rc) {
 		printk(KERN_ERR
@@ -845,7 +846,6 @@ static int __init ecryptfs_init(void)
 		printk(KERN_ERR "Failed to register filesystem\n");
 		goto out_free_kmem_caches;
 	}
-	kobj_set_kset_s(&ecryptfs_subsys, fs_subsys);
 	rc = do_sysfs_registration();
 	if (rc) {
 		printk(KERN_ERR "sysfs registration failed\n");