NFS: Fix nfs_reval_fsid()

We don't need to revalidate the fsid on the root directory. It suffices to
revalidate it on the current directory.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 23ecf03..7bcb3df 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -961,8 +961,8 @@
 		goto out_changed;
 
 	server = NFS_SERVER(inode);
-	/* Update the fsid if and only if this is the root directory */
-	if (inode == inode->i_sb->s_root->d_inode
+	/* Update the fsid? */
+	if (S_ISDIR(inode->i_mode)
 			&& !nfs_fsid_equal(&server->fsid, &fattr->fsid))
 		server->fsid = fattr->fsid;