freeradius:fuzzer_xlat: Use-after-poison in dict_by_protocol_substr

Detailed Report: https://oss-fuzz.com/testcase?key=5371377082499072 Project: freeradius Fuzzing Engine: libFuzzer Fuzz Target: fuzzerxlat Job Type: libfuzzerasanfreeradius Platform Id: linux Crash Type: Use-after-poison READ 1 Crash Address: 0x7bf7e27e1c61 Crash State: dictbyprotocolsubstr...