Fix build with gcc
Fix build with gcc

Twinklebear/OSPRay,Twinklebear/OSPRay,ospray/OSPRay,favreau/OSPRay,ospray/OSPRay,favreau/OSPRay,MengjiaoH/ospray,favreau/OSPRay,Twinklebear/OSPRay,MengjiaoH/ospray,ospray/OSPRay,MengjiaoH/ospray,MengjiaoH/ospray,wilsonCernWq/ospray,Twinklebear/OSPRay,ospray/OSPRay,favreau/OSPRay,MengjiaoH/ospray,wilsonCernWq/ospray,wilsonCernWq/ospray