dbus: Fix the CanSeek property getter

Close the D-Bus message when sending the value of the CanSeek property
in the Player object.
Signed-off-by: Mirsal Ennaime <mirsal@videolan.org>
(cherry picked from commit bc2987f3)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/control/dbus/dbus_player.c

@@ -420,6 +420,9 @@ DBUS_METHOD( CanSeek )
 
     MarshalCanSeek( p_this, &v );
 
+    if( !dbus_message_iter_close_container( &args, &v ) )
+        return DBUS_HANDLER_RESULT_NEED_MEMORY;
+
     REPLY_SEND;
 }