sysfs: move sysfs_dirent->s_children into sysfs_dirent->s_dir

Children list head is only meaninful for directory nodes.  Move it
into s_dir.  This doesn't save any space currently but it will with
further changes.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 60405a6..42b0327 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -1,6 +1,8 @@
 /* type-specific structures for sysfs_dirent->s_* union members */
 struct sysfs_elem_dir {
 	struct kobject		*kobj;
+	/* children list starts here and goes through sd->s_sibling */
+	struct sysfs_dirent	*children;
 };
 
 struct sysfs_elem_symlink {
@@ -28,7 +30,6 @@
 	atomic_t		s_active;
 	struct sysfs_dirent	*s_parent;
 	struct sysfs_dirent	*s_sibling;
-	struct sysfs_dirent	*s_children;
 	const char		*s_name;
 
 	union {