OSV-2026-632 Use-of-uninitialized-value in PKFormatConverter_InitializeConvert

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=506459298 Crash type: Use-of-uninitialized-value Crash state: PKFormatConverterInitializeConvert PKFormatConverterInitialize JXRHandler::read...