cras:cras_fl_media_fuzzer: Use-of-uninitialized-value in mix_add_scale_stride

Detailed Report: https://oss-fuzz.com/testcase?key=6749599955550208 Project: cras Fuzzing Engine: libFuzzer Fuzz Target: crasflmediafuzzer Job Type: libfuzzermsancras Platform Id: linux Crash Type: Use-of-uninitialized-value Crash Address: Crash State: mixaddscalestride crasmixaddscalestride...