Use new client_golang collectors package.

Signed-off-by: Ben Kochie <superq@gmail.com>

node_exporter.go

@@ -28,6 +28,7 @@ import (
 	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
 	"github.com/prometheus/client_golang/prometheus"
+	promcollectors "github.com/prometheus/client_golang/prometheus/collectors"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/prometheus/common/version"
 	"github.com/prometheus/exporter-toolkit/web"
@@ -57,8 +58,8 @@ func newHandler(includeExporterMetrics bool, maxRequests int, logger log.Logger)
 	}
 	if h.includeExporterMetrics {
 		h.exporterMetricsRegistry.MustRegister(
-			prometheus.NewProcessCollector(prometheus.ProcessCollectorOpts{}),
-			prometheus.NewGoCollector(),
+			promcollectors.NewProcessCollector(promcollectors.ProcessCollectorOpts{}),
+			promcollectors.NewGoCollector(),
 		)
 	}
 	if innerHandler, err := h.innerHandler(); err != nil {