perf lock: Remove stale comments

The comment was for symbol_conf.sort_by_name which was deleted already.
Let's get rid of the stale comments as well.

Acked-by: Ian Rogers <irogers@google.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230628200141.2739587-2-namhyung@kernel.org


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