Fix example for query-migrate-capabilities

Signed-off-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

qmp-commands.hx

@@ -2601,10 +2601,8 @@ Arguments:
 Example:
 
 -> { "execute": "query-migrate-capabilities" }
-<- { "return": {
-        "capabilities" :  [ { "capability" : "xbzrle", "state" : false } ]
-     }
-   }
+<- { "return": [ { "state": false, "capability": "xbzrle" } ] }
+
 EQMP
 
     {