perf pmu: Only print Using CPUID message once

With uncore event aliases which are duplicated over multiple PMUs the
"Using CPUID" message with -v could be printed many times.  Only print
it once.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1476393332-20732-3-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/pmu.c

@@ -504,6 +504,7 @@ static void pmu_add_cpu_aliases(struct list_head *head)
 	struct pmu_events_map *map;
 	struct pmu_event *pe;
 	char *cpuid;
+	static bool printed;
 
 	cpuid = getenv("PERF_CPUID");
 	if (cpuid)
@@ -513,7 +514,10 @@ static void pmu_add_cpu_aliases(struct list_head *head)
 	if (!cpuid)
 		return;
 
-	pr_debug("Using CPUID %s\n", cpuid);
+	if (!printed) {
+		pr_debug("Using CPUID %s\n", cpuid);
+		printed = true;
+	}
 
 	i = 0;
 	while (1) {