Fixed Error return value of ... is not checked (errcheck)

collectors/netstatMetric.go

@@ -11,6 +11,7 @@ import (
 	"bufio"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"os"
 	"strconv"
 	"strings"
@@ -65,7 +66,9 @@ func getCanonicalName(raw string, aliasToCanonical map[string]string) string {
 func (m *NetstatCollector) Init(config json.RawMessage) error {
 	m.name = "NetstatCollector"
 	m.parallel = true
-	m.setup()
+	if err := m.setup(); err != nil {
+		return fmt.Errorf("%s Init(): setup() call failed: %w", m.name, err)
+	}
 	m.lastTimestamp = time.Now()
 
 	const (