imagemagick:encoder_heic_fuzzer: Use-of-uninitialized-value in transform_4x4_luma_add_16_fallback

Detailed Report: https://oss-fuzz.com/testcase?key=6023032844976128 Project: imagemagick Fuzzing Engine: libFuzzer Fuzz Target: encoderheicfuzzer Job Type: libfuzzermsanimagemagick Platform Id: linux Crash Type: Use-of-uninitialized-value Crash Address: Crash State: transform4x4lumaadd16fallback...