The only problem I could possibly see with your light is if the other end was hard wired. (Cords as building wiring). If it is C&P you might get an argument that the assembly was not listed for C&P but not from me. BTW extra credit for a real cord connector and not a romex connector.
Actually for a similar use (attic lights) I am using jelly jars. At first mine were C&P too but when I was up there doing some other wiring I went ahead and ran Romex. That does give you some protection from damage to the bulb and from burning yourself but the CFL conversion mitigated that.
I doubt a jelly jar is much more than the lamp holder you have.
BTW a Home Inspector had no problem with this closet light
![[Linked Image from gfretwell.com]](http://gfretwell.com/electrical/closet_light.jpg)
