NFS: Fix a page leak in nfs_do_filldir()

nfs_do_filldir() must always free desc->page when it is done, otherwise
we end up leaking the page.

Also remove unused variable 'dentry'.

Signed-off-by: Trond Myklebust <[e-mail]>

fs/nfs/dir.c

···
 	int res = 0;
 	struct nfs_cache_array *array = NULL;
 	unsigned int d_type = DT_UNKNOWN;
-	struct dentry *dentry = NULL;
 
 	array = nfs_readdir_get_array(desc->page);
-	if (IS_ERR(array))
-		return PTR_ERR(array);
+	if (IS_ERR(array)) {
+		res = PTR_ERR(array);
+		goto out;
+	}
 
 	for (i = desc->cache_entry_index; i < array->size; i++) {
 		d_type = DT_UNKNOWN;
···
 		desc->eof = 1;
 
 	nfs_readdir_release_array(desc->page);
+out:
 	cache_page_release(desc);
-	if (dentry != NULL)
-		dput(dentry);
 	dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
 			(unsigned long long)*desc->dir_cookie, res);
 	return res;