s/ext/pbutil/g

The dependency matttproud/golang_protobuf_extensions changed its package
layout and thereby broke the Prometheus client_golang build. This fixes
it.

Author: peterbourgon

extraction/metricfamilyprocessor.go

@@ -20,7 +20,7 @@ import (
 
 	dto "github.com/prometheus/client_model/go"
 
-	"github.com/matttproud/golang_protobuf_extensions/ext"
+	"github.com/matttproud/golang_protobuf_extensions/pbutil"
 
 	"github.com/prometheus/client_golang/model"
 )
@@ -40,7 +40,7 @@ func (m *metricFamilyProcessor) ProcessSingle(i io.Reader, out Ingester, o *Proc
 	for {
 		family.Reset()
 
-		if _, err := ext.ReadDelimited(i, family); err != nil {
+		if _, err := pbutil.ReadDelimited(i, family); err != nil {
 			if err == io.EOF {
 				return nil
 			}

text/proto.go

@@ -18,7 +18,7 @@ import (
 	"io"
 
 	"github.com/golang/protobuf/proto"
-	"github.com/matttproud/golang_protobuf_extensions/ext"
+	"github.com/matttproud/golang_protobuf_extensions/pbutil"
 
 	dto "github.com/prometheus/client_model/go"
 )
@@ -27,7 +27,7 @@ import (
 // protobuf format and returns the number of bytes written and any error
 // encountered.
 func WriteProtoDelimited(w io.Writer, p *dto.MetricFamily) (int, error) {
-	return ext.WriteDelimited(w, p)
+	return pbutil.WriteDelimited(w, p)
 }
 
 // WriteProtoText writes the MetricFamily to the writer in text format and