Use spaces to indent and fix typo in tag.

Reviewed-by: schreiberal

doc/install.sgml

@@ -212,13 +212,13 @@
           kernel parameter <literal>nosmp</literal>.
         </para>
 
-	<para>
-	  It is recommended that you disable xen's automatic save of virtual
-	  machines at system shutdown and subsequent restore of them at reboot.
-	  To obtain this make sure the variable
-	  <listeral>XENDOMAINS_SAVE</literal> in the file
-	  <literal>/etc/default/xendomains</literal> is set to an empty value.
-	</para>
+        <para>
+          It is recommended that you disable xen's automatic save of virtual
+          machines at system shutdown and subsequent restore of them at reboot.
+          To obtain this make sure the variable
+          <literal>XENDOMAINS_SAVE</literal> in the file
+          <literal>/etc/default/xendomains</literal> is set to an empty value.
+        </para>
 
         <formalpara>
           <title>Debian</title>