fix(listing): narrow the list fallback per review

Signed-off-by: mr javad seydi <seydi.birjand@gmail.com>

cmd/metacache-entries.go

@@ -461,16 +461,6 @@ func (m metaCacheEntries) firstFound() (first *metaCacheEntry, n int) {
 	return first, n
 }
 
-// firstObject returns the first entry that contains object metadata.
-func (m metaCacheEntries) firstObject() *metaCacheEntry {
-	for i := range m {
-		if m[i].isObject() {
-			return &m[i]
-		}
-	}
-	return nil
-}
-
 // names will return all names in order.
 // Since this allocates it should not be used in critical functions.
 func (m metaCacheEntries) names() []string {