trivial compiler warning fix
trivial compiler warning fix

YangYangTL/oiio,cwilling/oiio,micler/oiio,sambler/oiio,lgritz/oiio,sambler/oiio,mcanthony/oiio,scott-wilson/oiio,sambler/oiio,lgritz/oiio,cwilling/oiio,mcanthony/oiio,mcanthony/oiio,micler/oiio,jeremyselan/oiio,mcanthony/oiio,scott-wilson/oiio,lgritz/oiio,YangYangTL/oiio,bdeluca/oiio,jeremyselan/oiio,OpenImageIO/oiio,jeremyselan/oiio,bdeluca/oiio,bdeluca/oiio,YangYangTL/oiio,scott-wilson/oiio,sambler/oiio,micler/oiio,YangYangTL/oiio,micler/oiio,OpenImageIO/oiio,OpenImageIO/oiio,bdeluca/oiio,scott-wilson/oiio,OpenImageIO/oiio,lgritz/oiio,cwilling/oiio,cwilling/oiio