st/oxr: Correctly validate view configurations

Part-of: <https://gitlab.freedesktop.org/monado/monado/-/merge_requests/2612>

src/xrt/state_trackers/oxr/oxr_api_system.c

···
 	OXR_VERIFY_INSTANCE_AND_INIT_LOG(&log, instance, inst, "xrGetViewConfigurationProperties");
 	OXR_VERIFY_ARG_TYPE_AND_NOT_NULL(&log, configurationProperties, XR_TYPE_VIEW_CONFIGURATION_PROPERTIES);
 	OXR_VERIFY_SYSTEM_AND_GET(&log, inst, systemId, sys);
+	OXR_VERIFY_VIEW_CONFIG_TYPE(&log, inst, viewConfigurationType);
 
 	return oxr_system_get_view_conf_properties(&log, sys, viewConfigurationType, configurationProperties);
 }