Simplify code

`gofmt -s` taught me that this is possible.

Signed-off-by: beorn7 <beorn@grafana.com>

prometheus/histogram.go

@@ -187,7 +187,7 @@ func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogr
 		desc:        desc,
 		upperBounds: opts.Buckets,
 		labelPairs:  makeLabelPairs(desc, labelValues),
-		counts:      [2]*histogramCounts{&histogramCounts{}, &histogramCounts{}},
+		counts:      [2]*histogramCounts{{}, {}},
 	}
 	for i, upperBound := range h.upperBounds {
 		if i < len(h.upperBounds)-1 {

prometheus/summary.go

@@ -208,7 +208,7 @@ func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
 		s := &noObjectivesSummary{
 			desc:       desc,
 			labelPairs: makeLabelPairs(desc, labelValues),
-			counts:     [2]*summaryCounts{&summaryCounts{}, &summaryCounts{}},
+			counts:     [2]*summaryCounts{{}, {}},
 		}
 		s.init(s) // Init self-collection.
 		return s