perf list: Avoid a hardcoded cpu PMU name

Use the first core PMU instead.

On a Raspberry Pi, before:

  $ perf list
  ...
    cpu/t1=v1[,t2=v2,t3 ...]/modifier                  [Raw hardware event descriptor]
         [(see 'man perf-list' on how to encode it)]
  ...

After:

  $ perf list
  ...
    armv8_cortex_a72/t1=v1[,t2=v2,t3 ...]/modifier     [Raw hardware event descriptor]
         [(see 'man perf-list' on how to encode it)]
  ...
  ```
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kang Minchul <tegongkang@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20230906234416.3472339-1-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/print-events.c

@@ -395,6 +395,8 @@ void print_symbol_events(const struct print_callbacks *print_cb, void *print_sta
  */
 void print_events(const struct print_callbacks *print_cb, void *print_state)
 {
+	char *tmp;
+
 	print_symbol_events(print_cb, print_state, PERF_TYPE_HARDWARE,
 			event_symbols_hw, PERF_COUNT_HW_MAX);
 	print_symbol_events(print_cb, print_state, PERF_TYPE_SOFTWARE,
@@ -418,17 +420,21 @@ void print_events(const struct print_callbacks *print_cb, void *print_state)
 			/*long_desc=*/NULL,
 			/*encoding_desc=*/NULL);
 
-	print_cb->print_event(print_state,
-			/*topic=*/NULL,
-			/*pmu_name=*/NULL,
-			"cpu/t1=v1[,t2=v2,t3 ...]/modifier",
-			/*event_alias=*/NULL,
-			/*scale_unit=*/NULL,
-			/*deprecated=*/false,
-			event_type_descriptors[PERF_TYPE_RAW],
-			"(see 'man perf-list' on how to encode it)",
-			/*long_desc=*/NULL,
-			/*encoding_desc=*/NULL);
+	if (asprintf(&tmp, "%s/t1=v1[,t2=v2,t3 ...]/modifier",
+		     perf_pmus__scan_core(/*pmu=*/NULL)->name) > 0) {
+		print_cb->print_event(print_state,
+				/*topic=*/NULL,
+				/*pmu_name=*/NULL,
+				tmp,
+				/*event_alias=*/NULL,
+				/*scale_unit=*/NULL,
+				/*deprecated=*/false,
+				event_type_descriptors[PERF_TYPE_RAW],
+				"(see 'man perf-list' on how to encode it)",
+				/*long_desc=*/NULL,
+				/*encoding_desc=*/NULL);
+		free(tmp);
+	}
 
 	print_cb->print_event(print_state,
 			/*topic=*/NULL,