skia/api_draw_functions: Use-of-uninitialized-value in sk_srcover_bgra_NUMBER

Project: https://skia.googlesource.com/skia.git Detailed report: https://oss-fuzz.com/testcase?key=6270009237045248 Project: skia Fuzzer: libFuzzerskiaapidrawfunctions Fuzz target binary: apidrawfunctions Job Type: libfuzzermsanskia Platform Id: linux Crash Type: Use-of-uninitialized-value Crash...