perf evsel: Fix period/freq terms setup

Stephane reported that we don't set properly PERIOD sample type for
events with period term defined.

Before:
  $ perf record -e cpu/cpu-cycles,period=1000/u ls
  $ perf evlist -v
  cpu/cpu-cycles,period=1000/u: ... sample_type: IP|TID|TIME|PERIOD, ...

After:
  $ perf record -e cpu/cpu-cycles,period=1000/u ls
  $ perf evlist -v
  cpu/cpu-cycles,period=1000/u: ... sample_type: IP|TID|TIME, ...

Setting PERIOD sample type based on period term setup.

Committer note:

When we use -c or a period=N term in the event definition, then we don't
need to ask the kernel, for this event, via perf_event_attr.sample_type
|= PERF_SAMPLE_PERIOD, to put the event period in each sample for this
event, as we know it already, it is in perf_event_attr.sample_period.

Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Stephane Eranian <eranian@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180201083812.11359-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evsel.c

@@ -745,12 +745,14 @@ static void apply_config_terms(struct perf_evsel *evsel,
 			if (!(term->weak && opts->user_interval != ULLONG_MAX)) {
 				attr->sample_period = term->val.period;
 				attr->freq = 0;
+				perf_evsel__reset_sample_bit(evsel, PERIOD);
 			}
 			break;
 		case PERF_EVSEL__CONFIG_TERM_FREQ:
 			if (!(term->weak && opts->user_freq != UINT_MAX)) {
 				attr->sample_freq = term->val.freq;
 				attr->freq = 1;
+				perf_evsel__set_sample_bit(evsel, PERIOD);
 			}
 			break;
 		case PERF_EVSEL__CONFIG_TERM_TIME: