Fix hard coded version of gcc in libffi

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@11477 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter06/libffi.xml

@@ -69,7 +69,7 @@ sed -e '/^includedir/ s/=.*$/=@includedir@/' \
           will be copied from the native system to a less capable 
           system, use the less capable system as a parameter. For details 
           about alternative system types, see <ulink 
-          url='https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/x86-Options.html'>
+          url='https://gcc.gnu.org/onlinedocs/gcc-&gcc-version;/gcc/x86-Options.html'>
           the x86 options in the gcc manual</ulink>.</para>
         </listitem>
       </varlistentry>