style: Fix spacing in ComputePieceSize comment (#3969)

Signed-off-by: yxxhero <aiopsclub@163.com>

Author: yxxhero

internal/util/util.go

@@ -28,7 +28,7 @@ const (
 
 // ComputePieceSize computes the piece size with specified fileLength.
 //
-// If the fileLength<0, which means failed to get fileLength
+// If the fileLength < 0, which means failed to get fileLength
 // and then use the DefaultPieceSize.
 func ComputePieceSize(length int64) uint32 {
 	if length <= 200*1024*1024 {