test-lib: retire "lint harder" optimization hack

`test_run_` in test-lib.sh "lints" the body of a test by sending it down a `sed chainlint.sed | grep` pipeline; this happens once for each test run by a test script. Although this pipeline may seem relatively cheap in isolation, it can become expensive when invoked 26800+ times by `make test`, once for each test run, despite the existence of only 16500+ test definitions across all tests scripts. This difference in the number of tests defined in the scripts (16500+) and the number of tests actually run by `make test` (26800+) is explained by the fact that some test scripts run a very large number of small tests, all driven by a series of functions/loops which fill in the test bodies. This means that certain test definitions are being linted repeatedly (tens or hundreds of times) unnecessarily. To avoid such unnecessary work, 2d86a96220 (t: avoid sed-based chain-linting in some expensive cases, 2021-05-13) added an optimization hack which allows individual scripts to manually suppress the unnecessary repeated linting of the same test definition. However, unlike chainlint.sed which checks a test body as the test is run, chainlint.pl checks each test definition just once, no matter how many times the test is run, thus the sort of optimization hack introduced by 2d86a96220 is no longer needed and can be retired. Therefore, revert 2d86a96220. Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>