Fix bug in ProgramPipelineObjectBenchmark Bug: angleproject:5102 Test: ProgramPipelineObjectBenchmark* Change-Id: I8d596ce7d6d9866b3333e675b40d9aad470525e6 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4647096 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: mohan maiya <m.maiya@samsung.com>