perf c2c: Update usage for showing memory events

Since commit b027cc6f ("perf c2c: Fix 'perf c2c record -e list' to
show the default events used"), "perf c2c" tool can show the memory
events properly, it's no reason to still suggest user to use the
command "perf mem record -e list" for showing events.

This patch updates the usage for showing memory events with command
"perf c2c record -e list".
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20201011121022.22409-1-leo.yan@linaro.org

tools/perf/builtin-c2c.c

@@ -2916,7 +2916,7 @@ static int perf_c2c__record(int argc, const char **argv)
 	bool event_set = false;
 	struct option options[] = {
 	OPT_CALLBACK('e', "event", &event_set, "event",
-		     "event selector. Use 'perf mem record -e list' to list available events",
+		     "event selector. Use 'perf c2c record -e list' to list available events",
 		     parse_record_events),
 	OPT_BOOLEAN('u', "all-user", &all_user, "collect only user level data"),
 	OPT_BOOLEAN('k', "all-kernel", &all_kernel, "collect only kernel level data"),