This makes it so consumers of `LogFile` should pass in how to get an
io.Reader to the requested number of lines to tail.
This is also much more efficient when tailing a large number of lines.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Upstream-commit: 94a10150f64a24793216f5324a34e62be3f31a2d
Component: engine
feccebcffe