Three small typos in man pages

The credit goes again to Lintian.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

man/ganeti.sgml

@@ -194,7 +194,7 @@
             <term>canceling</term>
             <listitem>
               <para>The jos is waiting for locks, but is has been
-              marked for cancelation. It will not transition to
+              marked for cancellation. It will not transition to
               <emphasis>running</emphasis>, but to
               <emphasis>canceled</emphasis>.
               </para>

man/gnt-cluster.sgml

@@ -317,7 +317,7 @@
       <para>
         The <option>--enabled-hypervisors</option> option allows you
         to set the list of hypervisors that will be enabled for
-        this cluster. Instance hypervisors can only be choosen from
+        this cluster. Instance hypervisors can only be chosen from
         the list of enabled hypervisors. Currently, the following
         hypervisors are available:
       </para>

man/gnt-instance.sgml

@@ -1142,7 +1142,7 @@ instance5: 11225
 
         <para>
           Use the <option>--all</option> to get info about all instances,
-          rather than explicitely passing the ones you're interested in.
+          rather than explicitly passing the ones you're interested in.
         </para>
       </refsect3>