bitbake: cooker: Ensure parsing failures stop the build

bitbake: cooker: Ensure parsing failures stop the build

Currently parsing failures still allow bitbake to continue on and try
and execute a build. This is clearly a bad idea and this patch adds in
more correct error handling and stops the build.

The use of sys.exit is nasty but this patches other usage in this function
so is at least consisent and its better than the current situation of
trying to execure a half parsed set of recipes. There are probably better
ways this could be improved to use to stop the build.

(Bitbake rev: 22756e9c0f1da33ba2c6e881b214577a610b7986)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>