Kernel installation update

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@494 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter05/kernel-exp.xml

@@ -1,6 +1,11 @@
 <sect2>
 <title>Command explanations</title>
 
+<para>
+<userinput>make mrproper:</userinput> This will ensure that the kernel
+tree is absolutely clean.
+</para>
+
 <para>
 <userinput>yes "" | make config:</userinput> This runs make config and
 answers with the default answer to every question the config script asks