command/runqueue: Fix shutdown logic

If you hit Ctrl+C at the right point, the system processes the request
but merrily continues building. It turns out finish_runqueue() is called
but this doesn't stop the later generation and execution of the
runqueue.

This patch adjusts some of the conditionals to ensure the build really
does stop.

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