Clarify that the stonith-timeout formula is a minimum (#364)

bsc#1218275
jsc#DOCTEAM-1207

xml/ha_storage_protection.xml

@@ -372,13 +372,13 @@
   </para>
    <example xml:id="ex-ha-storage-protect-sbd-timings">
     <title>Formula for timeout calculation</title>
-    <screen>Timeout (msgwait) >= (Timeout (watchdog) * 2)
-stonith-timeout = Timeout (msgwait) + 20%</screen>
+    <screen>Timeout (msgwait) &gt;= (Timeout (watchdog) * 2)
+stonith-timeout &gt;= Timeout (msgwait) + 20%</screen>
    </example>
    <para>
     For example, if you set the watchdog timeout to <literal>120</literal>,
-    set the <literal>msgwait</literal> timeout to <literal>240</literal> and the
-    <literal>stonith-timeout</literal> to <literal>288</literal>.
+    set the <literal>msgwait</literal> timeout to at least <literal>240</literal> and the
+    <literal>stonith-timeout</literal> to at least <literal>288</literal>.
    </para>
     <para>
      If you use the bootstrap scripts provided by the &crmshell; to set up a