fix possible crashes on deleteMarker replication (#11308)

Delete marker can have `metaSys` set to nil, that
can lead to crashes after the delete marker has
been healed.

Additionally also fix isObjectDangling check
for transitioned objects, that do not have parts
should be treated similar to Delete marker.

cmd/xl-storage-format-v1.go

@@ -182,10 +182,6 @@ func (m *xlMetaV1Object) ToFileInfo(volume, path string) (FileInfo, error) {
 	if !m.valid() {
 		return FileInfo{}, errFileCorrupt
 	}
-	var transitionStatus string
-	if st, ok := m.Meta[ReservedMetadataPrefixLower+"transition-status"]; ok {
-		transitionStatus = st
-	}
 	fi := FileInfo{
 		Volume:    volume,
 		Name:      path,
@@ -197,8 +193,8 @@ func (m *xlMetaV1Object) ToFileInfo(volume, path string) (FileInfo, error) {
 		VersionID: m.VersionID,
 		DataDir:   m.DataDir,
 	}
-	if transitionStatus != "" {
-		fi.TransitionStatus = transitionStatus
+	if st, ok := m.Meta[ReservedMetadataPrefixLower+"transition-status"]; ok {
+		fi.TransitionStatus = st
 	}
 	return fi, nil
 }