Fix for OpenImageIO not being found on some linux systems.
Fix for OpenImageIO not being found on some linux systems.

johnhaddon/OpenShadingLanguage,mcanthony/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,rlmh/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,lgritz/OpenShadingLanguage,juvenal/OpenShadingLanguage,sjparker/OpenShadingLanguage,gzorin/OpenShadingLanguage,lgritz/OpenShadingLanguage,sjparker/OpenShadingLanguage,aconty/OpenShadingLanguage,imageworks/OpenShadingLanguage,Anteru/OpenShadingLanguage,Anteru/OpenShadingLanguage,gzorin/OpenShadingLanguage,svenstaro/OpenShadingLanguage,mcanthony/OpenShadingLanguage,juvenal/OpenShadingLanguage,svenstaro/OpenShadingLanguage,lgritz/OpenShadingLanguage,aconty/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,rlmh/OpenShadingLanguage,svenstaro/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,brechtvl/OpenShadingLanguage,juvenal/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,Anteru/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,lgritz/OpenShadingLanguage,juvenal/OpenShadingLanguage,imageworks/OpenShadingLanguage,lgritz/OpenShadingLanguage,gzorin/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,gzorin/OpenShadingLanguage,svenstaro/OpenShadingLanguage,mcanthony/OpenShadingLanguage,imageworks/OpenShadingLanguage,aconty/OpenShadingLanguage,brechtvl/OpenShadingLanguage,imageworks/OpenShadingLanguage,brechtvl/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,brechtvl/OpenShadingLanguage,aconty/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,sjparker/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,gzorin/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,imageworks/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,rlmh/OpenShadingLanguage,sjparker/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,Anteru/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,mcanthony/OpenShadingLanguage,rlmh/OpenShadingLanguage,aconty/OpenShadingLanguage,brechtvl/OpenShadingLanguage