windows/registry: remove debugging dreg

copy of CL 13828 change

Change-Id: I48ea36171281eed8e59b92e130c762142fb94604
Reviewed-on: https://go-review.googlesource.com/13829Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

windows/registry/value.go

@@ -310,7 +310,6 @@ loopItems:
 				break
 			}
 			if err == syscall.ERROR_MORE_DATA {
-				println(len(buf), l)
 				// Double buffer size and try again.
 				l = uint32(2 * len(buf))
 				buf = make([]uint16, l)