Avoid printing i/o closed pipe error message (#6654)

Since refactoring to GetObjectNInfo style, there are many cases
when i/o closed pipe is printed like, downloading an object
with wrong encryption key. This PR removes the log.

cmd/erasure-utils.go

@@ -20,7 +20,6 @@ import (
 	"bytes"
 	"context"
 	"io"
-	"strings"
 
 	"github.com/klauspost/reedsolomon"
 	"github.com/minio/minio/cmd/logger"
@@ -82,7 +81,9 @@ func writeDataBlocks(ctx context.Context, dst io.Writer, enBlocks [][]byte, data
 		if write < int64(len(block)) {
 			n, err := io.Copy(dst, bytes.NewReader(block[:write]))
 			if err != nil {
-				logger.LogIf(ctx, err)
+				if err != io.ErrClosedPipe {
+					logger.LogIf(ctx, err)
+				}
 				return 0, err
 			}
 			totalWritten += n
@@ -92,7 +93,7 @@ func writeDataBlocks(ctx context.Context, dst io.Writer, enBlocks [][]byte, data
 		n, err := io.Copy(dst, bytes.NewReader(block))
 		if err != nil {
 			// The writer will be closed incase of range queries, which will emit ErrClosedPipe.
-			if !strings.Contains(err.Error(), "read/write on closed pipe") {
+			if err != io.ErrClosedPipe {
 				logger.LogIf(ctx, err)
 			}
 			return 0, err