build: fix test for --nocompress option

Richard W.M. Jones wrote:
> On Wed, Jul 29, 2009 at 10:50:44PM +0200, Jim Meyering wrote:
>> The test for febootstrap-to-initramfs' --nocompress option
>> was always failing for me on F11.  Here's why:
> [...]
>
> Ouch that's obscure.  I've applied this patch and the previous
> one you sent too.  Thanks!

Our messages crossed.
Rebasing my fixed patch and adjusting the log:

>From 9e7846da50ceeee57187f703835bd3975e789719 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering@redhat.com>
Date: Wed, 29 Jul 2009 16:33:02 -0400
Subject: [PATCH] build: quote the other option test similarly

* configure.ac: Quote properly.