Fix compile warning.
Fix compile warning.

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