Fixed issues with decompress.Decoder

internal/decompress/lz4.go

@@ -16,12 +16,3 @@ func (l Lz4) Reset(old, src io.Reader) error {
 	old.(*lz4.Reader).Reset(src)
 	return nil
 }
-
-func (l Lz4) Decode(in []byte, outSize int) (out []byte, err error) {
-	out = make([]byte, outSize)
-	outLen, err := lz4.UncompressBlock(in, out)
-	if outLen < outSize {
-		out = out[:outLen]
-	}
-	return
-}