evince: uninitialized memory use in function tiff_document_render() and tiff_document_get_thumbnail()

The tiffdocumentrender and tiffdocumentgetthumbnail functions in the TIFF document backend in GNOME Evince through 3.32.0 did not handle errors from TIFFReadRGBAImageOriented, leading to uninitialized memory use when processing certain TIFF image files...