After JDK-8343832, `make test-prebuilt` fails with `JTREG_OPTIONS="-l"` set:
```
$ JTREG_OPTIONS="-l" TEST=:tier1_part1 make test-prebuilt
...
Tests found: 1,095
Finished running test 'jtreg:test/jdk:tier1_part1'
Test report is stored in build/run-test-prebuilt/test-results/jtreg_test_jdk_tier1_part1
bash: line 1: printf: <<: invalid number
make[2]: *** [RunTests.gmk:1323: run-test-report] Error 1
make[1]: *** [make/RunTestsPrebuilt.gmk:300: test-prebuilt] Error 2
make: *** [/workspace/make/Global.gmk:124: test-prebuilt] Error 2
```