Rationale correction

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@10618 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

prologue/why.xml

@@ -235,7 +235,7 @@
         <para>Gperf</para>
 
         <para>This package a program that generates a perfect hash function 
-        from a key set.  It is required for systemd.
+        from a key set.  It is required for Eudev.
         </para>
       </listitem>