Revert "mips64el: chapter06/xz: Work around a libtool bug"

This reverts commit 91c8848da1.

The workaround is no longer needed with xz-5.6.3.

chapter06/xz.xml

@@ -49,27 +49,8 @@
             --host=$LFS_TGT                   \
             --build=$(build-aux/config.guess) \
             --disable-static                  \
-            ac_cv_prog_FILECMD=file           \
             --docdir=/usr/share/doc/xz-&xz-version;</userinput></screen>
 
-    <variablelist>
-      <title>The meaning of the new configure options:</title>
-
-      <!-- https://git.savannah.gnu.org/cgit/libtool.git/commit/?id=9a4a02615c9e -->
-      <varlistentry>
-        <term><parameter>ac_cv_prog_FILECMD=file</parameter></term>
-        <listitem>
-          <para>Works around an issue in the shipped libtool copy causing
-          the configure script fail to find the <command>file</command>
-          command of the host distro.  The issue is harmless for most
-          architectures, but it can make
-          <parameter>--disable-static</parameter> ineffective for
-          MIPS.</para>
-        </listitem>
-      </varlistentry>
-    </variablelist>
-
-
    <para>Compile the package:</para>
 
 <screen><userinput remap="make">make</userinput></screen>

chapter08/xz.xml

@@ -52,7 +52,6 @@
 
 <screen><userinput remap="configure">./configure --prefix=/usr    \
             --disable-static \
-            ac_cv_prog_FILECMD=file \
             --docdir=/usr/share/doc/xz-&xz-version;</userinput></screen>
 
     <para>Compile the package:</para>