imagemagick/encoder_mac_fuzzer: Use-of-uninitialized-value in PushColormapIndex

Project: https://github.com/imagemagick/imagemagick.git Detailed report: https://oss-fuzz.com/testcase?key=6449845712715776 Project: imagemagick Fuzzer: libFuzzerimagemagickencodermacfuzzer Fuzz target binary: encodermacfuzzer Job Type: libfuzzermsanimagemagick Platform Id: linux Crash Type:...