cleanup: make blob sizes easier to understand

This is a followup to https://github.com/distribution/distribution/pull/4139

Signed-off-by: Milos Gajdos <milosthegajdos@gmail.com>

registry/storage/filereader.go

@@ -15,7 +15,7 @@ import (
 // set this correctly, so we may want to leave it to the driver. For
 // out of process drivers, we'll have to optimize this buffer size for
 // local communication.
-const fileReaderBufferSize = 4 << 20
+const fileReaderBufferSize = 4 * 1024 * 1024
 
 // remoteFileReader provides a read seeker interface to files stored in
 // storagedriver. Used to implement part of layer interface and will be used

registry/storage/io.go

@@ -9,7 +9,7 @@ import (
 )
 
 const (
-	maxBlobGetSize = 4 << 20
+	maxBlobGetSize = 4 * 1024 * 1024
 )
 
 func getContent(ctx context.Context, driver driver.StorageDriver, p string) ([]byte, error) {