Unpack hierarchy - jethro vs. krogoth

[<colin.helliwell@ln-systems.com>]

Is there a change to recipe parsing and/or variables between jethro and
krogoth?
I'm migrating from the former to the latter and have hit a patch failure.
Looking at the unpacked source, jethro has the relevant file at
    build/tmp/work/XXX-poky-linux-gnueabi/linmux/3.0.2-r0/driver/
whereas krogoth has it at
    build/tmp/work/XXX-poky-linux-gnueabi/linmux/3.0.2-r0/driver/driver/

Indeed, all the sources have been unpacked under an additional 'driver'
directory level .e.g.
    src/driver/*  ->  3.0.2-r0/driver/driver/
    src/config/*  ->  3.0.2-r0/driver/config/
instead of 
    src/driver/*  ->  3.0.2-r0/driver/
    src/config/*  ->  3.0.2-r0/config/


The recipe includes
SRC_URI = "file://driver/*.c \
           file://driver/*.h \
           file://Makefile \
           file://COPYING \
          "
FILESEXTRAPATHS_prepend := "${BSPDIR}/../Apps/MyDriver/src:"
S = "${WORKDIR}"

As I say, it works on jethro...!