move d_rcu from overlapping d_child to overlapping d_alias

commit 946e51f2bf37f1656916eb75bd0742ba33983c28 upstream.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2:
 - Apply name changes in all the different places we use d_alias and d_child
 - Move the WARN_ON() in __d_free() to d_free() as we don't have dentry_free()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[lizf: Backported to 3.4:
 - adjust context
 - need one more name change in debugfs]
diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index 4ca6f5c..b242f69 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -62,7 +62,7 @@
 		 */
 		spin_lock(&sb->s_root->d_inode->i_lock);
 		spin_lock(&sb->s_root->d_lock);
-		list_del_init(&sb->s_root->d_alias);
+		list_del_init(&sb->s_root->d_u.d_alias);
 		spin_unlock(&sb->s_root->d_lock);
 		spin_unlock(&sb->s_root->d_inode->i_lock);
 	}