use-of-uninitialized-value in PackPlanarWords

use-of-uninitialized-value in PackPlanarWords: a task in MiMo-V2.6-RL-oss: Agentic RL Environments (MiMo RL release). MemorySanitizer: use-of-uninitialized-value in function PackPlanarWords in file lcms/src/cmspack.c