nfs: remove unnecessary dentry_unhash on rmdir/rename_dir

NFS has no problems with lingering references to unlinked directory
inodes.

CC: Trond Myklebust <Trond.Myklebust@netapp.com>
CC: linux-nfs@vger.kernel.org
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/nfs/dir.c

@@ -1748,8 +1748,6 @@ static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
 	dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n",
 			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
 
-	dentry_unhash(dentry);
-
 	error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
 	/* Ensure the VFS deletes this inode */
 	if (error == 0 && dentry->d_inode != NULL)
@@ -1959,9 +1957,6 @@ static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		 new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
 		 new_dentry->d_count);
 
-	if (new_inode && S_ISDIR(new_inode->i_mode))
-		dentry_unhash(new_dentry);
-
 	/*
 	 * For non-directories, check whether the target is busy and if so,
 	 * make a copy of the dentry and then do a silly-rename. If the