perf annotate: Remove unused len parameter from annotation_line__print()

It's not used anywhere, let's get rid of it.

Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250310224925.799005-3-namhyung@kernel.org


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