[code coverage] Remove libfuzzer_tests from fuzzer target list.

libfuzzer_tests is not a fuzzer, and was incorrectly added as a fuzzer target.

TBR=jbudorick

Change-Id: Ie10441735782b9a971087a23b86eff8fa991c732
Reviewed-on: https://chromium-review.googlesource.com/c/1379317
Commit-Queue: Shuotao Gao <stgao@chromium.org>
Reviewed-by: Abhishek Arya <inferno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#616960}
3 files changed