Fix regex in the test of fuzzer.FileWriterDecorator to avoid failure on Windows.
Fix regex in the test of fuzzer.FileWriterDecorator to avoid failure on Windows.

akosthekiss/fuzzinator,renatahodovan/fuzzinator,renatahodovan/fuzzinator,akosthekiss/fuzzinator,renatahodovan/fuzzinator,renatahodovan/fuzzinator,akosthekiss/fuzzinator,akosthekiss/fuzzinator