internal/reexec: fix broken link to Docker/Moby in comment (#31859)

Hey team—noticed a dead link, replaced it with a working URL

https://github.com/moby/moby/blob/master/pkg/reexec/reexec.go - old link

https://github.com/moby/moby/blob/master/pkg/reexec/reexec_deprecated.go
- new link

Author: dizer-ti

internal/reexec/reexec.go

@@ -1,5 +1,5 @@
 // This file originates from Docker/Moby,
-// https://github.com/moby/moby/blob/master/pkg/reexec/reexec.go
+// https://github.com/moby/moby/blob/master/pkg/reexec/reexec_deprecated.go
 // Licensed under Apache License 2.0: https://github.com/moby/moby/blob/master/LICENSE
 // Copyright 2013-2018 Docker, Inc.
 //