perf header: Fix pipe mode header dumping

The pipe mode header dumping was accidentally removed when tracing of
header feature events in pipe mode was added.

Minor spelling tweak to header test failure message.

Fixes: 61051f9a ("perf header: In pipe mode dump features without --header/-I")
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20250703042000.2740640-1-irogers@google.com


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