Fixes [BUGID: #390]
The custom de-checkpoint routines used in createme/patchme
destroyed data each run. This meant that incremental and
expermental work couldn't be done directly in the kernel source
tree itself. Using the more robust kgit-checkpoint allows that
data to be persistent (until a clean is done).
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>