Tag correction.

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@4659 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter06/readline.xml

@@ -66,7 +66,7 @@ location:</para>
 
 <screen><userinput>mv /lib/lib{readline,history}.a /usr/lib</userinput></screen>
 
-<para>Next we will remove the old, <filename>.so</filename> files in
+<para>Next we will remove the old, <filename class="extension">.so</filename> files in
 <filename class="directory">/lib</filename> and relink them into
 <filename class="directory">/usr/lib</filename>.</para>