Fix an XML error spotted by Bart.



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@9218 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/docs/xml/FAQ.xml b/docs/xml/FAQ.xml
index 8958b3a..109ea10 100644
--- a/docs/xml/FAQ.xml
+++ b/docs/xml/FAQ.xml
@@ -572,7 +572,7 @@
     <para>Is it possible to attach Valgrind to a program that is already
     running?</para>
   </question>
-  <answer id="a-undeferrors">
+  <answer id="a-attach">
     <para>No.  The environment that Valgrind provides for running programs
     is significantly different to that for normal programs, e.g. due to
     different layout of memory.  Therefore Valgrind has to have full control