simplify hasCaller check

json_formatter.go

@@ -53,12 +53,7 @@ func (f *JSONFormatter) Format(entry *Entry) ([]byte, error) {
 		}
 	}
 
-	reportCaller := false
-	if entry.Logger != nil {
-		reportCaller = entry.Logger.ReportCaller
-	}
-
-	prefixFieldClashes(data, reportCaller)
+	prefixFieldClashes(data, entry.HasCaller())
 
 	timestampFormat := f.TimestampFormat
 	if timestampFormat == "" {
@@ -68,7 +63,7 @@ func (f *JSONFormatter) Format(entry *Entry) ([]byte, error) {
 	data[f.FieldMap.resolve(FieldKeyTime)] = entry.Time.Format(timestampFormat)
 	data[f.FieldMap.resolve(FieldKeyMsg)] = entry.Message
 	data[f.FieldMap.resolve(FieldKeyLevel)] = entry.Level.String()
-	if reportCaller {
+	if entry.HasCaller() {
 		data[f.FieldMap.resolve(FieldKeyCaller)] = entry.Caller
 	}
 	serialized, err := json.Marshal(data)