NFS: remove special-case revalidate in nfs_opendir()

Commit f5a73672 ("NFS: allow close-to-open cache semantics to
apply to root of NFS filesystem") added a call to
__nfs_revalidate_inode() to nfs_opendir to as the lookup
process wouldn't reliable do this.

Subsequent commit a3fbbde7 ("VFS: we need to set LOOKUP_JUMPED
on mountpoint crossing") make this unnecessary.  So remove the
unnecessary code.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/dir.c

@@ -118,13 +118,6 @@ nfs_opendir(struct inode *inode, struct file *filp)
 		goto out;
 	}
 	filp->private_data = ctx;
-	if (filp->f_path.dentry == filp->f_path.mnt->mnt_root) {
-		/* This is a mountpoint, so d_revalidate will never
-		 * have been called, so we need to refresh the
-		 * inode (for close-open consistency) ourselves.
-		 */
-		__nfs_revalidate_inode(NFS_SERVER(inode), inode);
-	}
 out:
 	put_rpccred(cred);
 	return res;