perf tools: Remove unused color_fwrite_lines

color_fwrite_lines() was added by 2009's commit
8fc0321f ("perf_counter tools: Add color terminal output support")

but has never been used.

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20241009003938.254936-1-linux@treblig.org


Signed-off-by: Namhyung Kim <namhyung@kernel.org>