Revert "Merge pull request #132 from eddc005/feat-pcap"

This reverts commit c453020349, reversing
changes made to 5723490a6c.

io/nfqueue.go

@@ -281,11 +281,6 @@ func (n *nfqueuePacketIO) Close() error {
 	return n.n.Close()
 }
 
-// nfqueue IO does not issue shutdown
-func (n *nfqueuePacketIO) SetCancelFunc(cancelFunc context.CancelFunc) error {
-	return nil
-}
-
 func (n *nfqueuePacketIO) setupNft(local, rst, remove bool) error {
 	rules, err := generateNftRules(local, rst)
 	if err != nil {