Editorial touchup for clarity

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@11330 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter06/systemd.xml

@@ -49,7 +49,8 @@
 
     <para>Prepare systemd for compilation:</para>
 
-    <screen><userinput remap="configure">cd    build
+    <screen><userinput remap="configure">mkdir -p build
+cd       build
 
 LANG=en_US.UTF-8                   \
 meson --prefix=/usr                \