Move potential error earlier

[radarhere]

For

Pillow/src/_webp.c

Lines 956 to 974 in 6b71090

	static int
	setup_module(PyObject *m) {
	PyObject *d = PyModule_GetDict(m);
	addMuxFlagToModule(m);
	addAnimFlagToModule(m);
	addTransparencyFlagToModule(m);
	PyDict_SetItemString(
	d, "webpdecoder_version", PyUnicode_FromString(WebPDecoderVersion_str()));
	#ifdef HAVE_WEBPANIM
	/* Ready object types */
	if (PyType_Ready(&WebPAnimDecoder_Type) < 0 ||
	PyType_Ready(&WebPAnimEncoder_Type) < 0) {
	return -1;
	}
	#endif
	return 0;
	}

this PR rearranges the code to run the PyType_Ready conditional first, so it the code fails earlier, and d is not created for potentially no reason (m isn't used if setup_module returns -1).