This reduces allocs and bytes used per log entry significantly as well as some improvement to time per log operation. Each log driver, however, must put messages back in the pool once they are finished with the message. Signed-off-by: Brian Goff <cpuguy83@gmail.com> Upstream-commit: 3f4fccb65f0ef286c9c4e0f01c4ae7bb09a6ad89 Component: engine