Added note not to remove binutils-build

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@2494 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter05/binutils-pass1-inst.xml

@@ -57,6 +57,8 @@ variable.</para></listitem>
 <para><screen><userinput>make -C ld clean
 make -C ld LIB_PATH=/stage1/lib</userinput></screen></para>
 
+<para>Do not remove the binutils-build directory. We will use it again
+later on in this chapter.</para>
 
 </sect2>