remove checkBucketExist check entirely to avoid fan-out calls (#18917)

Each Put, List, Multipart operations heavily rely on making
GetBucketInfo() call to verify if bucket exists or not on
a regular basis. This has a large performance cost when there
are tons of servers involved.

We did optimize this part by vectorizing the bucket calls,
however its not enough, beyond 100 nodes and this becomes
fairly visible in terms of performance.

cmd/metacache-server-pool.go

@@ -58,9 +58,10 @@ func renameAllBucketMetacache(epPath string) error {
 // Other important fields are Limit, Marker.
 // List ID always derived from the Marker.
 func (z *erasureServerPools) listPath(ctx context.Context, o *listPathOptions) (entries metaCacheEntriesSorted, err error) {
-	if err := checkListObjsArgs(ctx, o.Bucket, o.Prefix, o.Marker, z); err != nil {
+	if err := checkListObjsArgs(ctx, o.Bucket, o.Prefix, o.Marker); err != nil {
 		return entries, err
 	}
+
 	// Marker points to before the prefix, just ignore it.
 	if o.Marker < o.Prefix {
 		o.Marker = ""
@@ -313,6 +314,9 @@ func (z *erasureServerPools) listMerged(ctx context.Context, o listPathOptions,
 	}
 
 	if isAllNotFound(errs) {
+		if isAllVolumeNotFound(errs) {
+			return errVolumeNotFound
+		}
 		return nil
 	}