XL: Fix GetObject erasure decode issues. (#1793)

fs-v1-metadata.go

@@ -57,7 +57,7 @@ func (m *fsMetaV1) AddObjectPart(partNumber int, partName string, partETag strin
 
 // readFSMetadata - returns the object metadata `fs.json` content.
 func (fs fsObjects) readFSMetadata(bucket, object string) (fsMeta fsMetaV1, err error) {
-	buffer := make([]byte, blockSize)
+	buffer := make([]byte, blockSizeV1)
 	n, err := fs.storage.ReadFile(bucket, path.Join(object, fsMetaJSONFile), int64(0), buffer)
 	if err != nil {
 		return fsMetaV1{}, err