Factor out perf_prepare_header() so that it can call
perf_prepare_sample() without a header if not needed.

Also it checks the filtered_sample_type to avoid duplicate
work when perf_prepare_sample() is called twice (or more).
Suggested-by: NPeter Zijlstr <peterz@infradead.org>
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
Tested-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NSong Liu <song@kernel.org>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230118060559.615653-8-namhyung@kernel.org