stream: fixed comment of NopEncoder simplified Write for noop

stream/encoding.go

@@ -34,7 +34,7 @@ type Encoder interface {
 	GetDst() io.Writer
 }
 
-// NopEncoder returns an
+// NopEncoder returns an Encoder that performs no operation.
 func NopEncoder(dst io.Writer) Encoder {
 	return noop{dst}
 }
@@ -45,8 +45,7 @@ type noop struct {
 
 // Write implements io.Writer.
 func (e noop) Write(p []byte) (int, error) {
-	n, err := e.dst.Write(p)
-	return n, err
+	return e.dst.Write(p)
 }
 
 func (e noop) GetDst() io.Writer { return e.dst }