NFS: Do not flush the readdir cache in nfs_dentry_iput()

The original premise in commit 83672d39 ("NFS: Fix directory caching
problem - with test case and patch.") was that readdirplus was caching
attribute information and replaying it later. This is no longer the
case.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/dir.c

@@ -1727,10 +1727,6 @@ static void nfs_drop_nlink(struct inode *inode)
  */
 static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
 {
-	if (S_ISDIR(inode->i_mode))
-		/* drop any readdir cache as it could easily be old */
-		nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
-
 	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
 		nfs_complete_unlink(dentry, inode);
 		nfs_drop_nlink(inode);