note about sed line break

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@1068 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter06/file-inst.xml

@@ -1,7 +1,10 @@
 <sect2>
 <title>Installation of File</title>
 
-<para>Install File by running the following commands:</para>
+<para>Note that the sed used in this installation only works if the line
+break is placed exactly where it is in the book.  Don't try and put it
+all on one line otherwise it won't work.  Install File by running the 
+following commands:</para>
 
 <para><screen><userinput>cp -f readelf.h readelf.h.backup &amp;&amp;</userinput>
 <userinput>sed '/#define __/a \</userinput>