uniq: use helper function for file creation #1624

Job	Run time
Build the fuzzers	2m 24s
Build and test uufuzz examples	58s
Fuzz (fuzz_cut, false)	2m 20s
Fuzz (fuzz_seq, false)	2m 17s
Fuzz (fuzz_split, false)	1s
Fuzz (fuzz_printf, true)	1s
Fuzz (fuzz_date, true)	1s
Fuzz (fuzz_parse_glob, true)	23s
Fuzz (fuzz_echo, true)	2m 34s
Fuzz (fuzz_sort, false)	5m 27s
Fuzz (fuzz_tr, false)	5m 27s
Fuzz (fuzz_cksum, false)	2m 15s
Fuzz (fuzz_seq_parse_number, false)	1s
Fuzz (fuzz_non_utf8_paths, true)	1s
Fuzz (fuzz_env, false)	2m 5s
Fuzz (fuzz_expr, true)	1s
Fuzz (fuzz_parse_time, false)	1s
Fuzz (fuzz_test, true)	1s
Fuzz (fuzz_wc, false)	1s
Fuzz (fuzz_dirname, true)	1s
Fuzz (fuzz_parse_size, false)	1s
Fuzzing Summary	6s
	26m 27s

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