perf annotate: Pass perf_evsel instead of just evsel->idx

The code gets shorter and we'll be able to use evsel->evlist in a
followup patch.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-t0s7vy19wq5kak74kavm8swf@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>