fix: use file.opt instead of opt when setting logger creating a file instance. (#97)

* fix: use file.opt instead of opt when setting logger.

If pe.New function is called with nil as opts parameter, panic occurs due to comparing opts.logger(which opt is nil), so use file.opts instead.

* fix: use file.opts.logger for NewBytes function

Author: Snshadow

file.go

@@ -144,12 +144,12 @@ func New(name string, opts *Options) (*File, error) {
 	}
 
 	var logger log.Logger
-	if opts.Logger == nil {
+	if file.opts.Logger == nil {
 		logger = log.NewStdLogger(os.Stdout)
 		file.logger = log.NewHelper(log.NewFilter(logger,
 			log.FilterLevel(log.LevelError)))
 	} else {
-		file.logger = log.NewHelper(opts.Logger)
+		file.logger = log.NewHelper(file.opts.Logger)
 	}
 
 	file.data = data
@@ -176,7 +176,7 @@ func NewBytes(data []byte, opts *Options) (*File, error) {
 	}
 
 	var logger log.Logger
-	if opts.Logger == nil {
+	if file.opts.Logger == nil {
 		logger = log.NewStdLogger(os.Stdout)
 		file.logger = log.NewHelper(log.NewFilter(logger,
 			log.FilterLevel(log.LevelError)))