NFS: Fix atime revalidation in readdir()

NFSv3 will correctly update atime on a readdir call, so there is no need to
set the NFS_INO_INVALID_ATIME flag unless the call to nfs_refresh_inode()
fails.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index c7ca5d7..0ae263c 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -607,6 +607,9 @@
 
 	nfs_fattr_init(&dir_attr);
 	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
+
+	nfs_invalidate_atime(dir);
+
 	nfs_refresh_inode(dir, &dir_attr);
 	dprintk("NFS reply readdir: %d\n", status);
 	return status;