schema,tests: Use vpxmigr for host migrate transport capability

Commit id 'e4938ce2f' changed the esx_driver to use 'vpxmigr'
instead of esx for virCapabilitiesAddHostMigrateTransport, so
update the capabilities to allow virt-xml-validate to pass and
update the test to use the newer name.

Signed-off-by: John Ferlan <jferlan@redhat.com>
ACKed-by Michal Privoznik <mprivozn@redhat.com>

docs/schemas/capability.rng

@@ -160,7 +160,7 @@
           <oneOrMore>
             <element name='uri_transport'>
               <choice>
-                <value>esx</value>
+                <value>vpxmigr</value>
                 <value>tcp</value>
               </choice>
             </element>

tests/vmx2xmltest.c

@@ -30,7 +30,7 @@ testCapsInit(void)
     if (caps == NULL)
         return;
 
-    virCapabilitiesAddHostMigrateTransport(caps, "esx");
+    virCapabilitiesAddHostMigrateTransport(caps, "vpxmigr");
 
     /* i686 guest */
     guest =