composefs: trim / from paths

it solves the following error when pulling the alpine image:

mkcomposefs: Parent directory missing for /bin/

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

pkg/chunked/dump/dump.go

@@ -94,7 +94,7 @@ func getStMode(mode uint32, typ string) (uint32, error) {
 }
 
 func dumpNode(out io.Writer, links map[string]int, verityDigests map[string]string, entry *internal.FileMetadata) error {
-	path := entry.Name
+	path := strings.TrimRight(entry.Name, "/")
 	if path == "" {
 		path = "/"
 	} else if path[0] != '/' {