undefined-behavior in test multiline parser

undefined-behavior in test multiline parser: a task in MiMo-V2.6-RL-harbor-cyber: MiMo-V2.6-RL Cyber (Harbor) (Harbor dataset). UndefinedBehaviorSanitizer: undefined-behavior in function test multiline parser in file fluent-bit/tests/internal/fuzzers/multiline fuzzer.c