bml: log the actual error
bml: add return values to the tools

This way test machine can also detect failure in the ipc case. As now the host
crashes the test-runner is not seeing the crashes.
bml: free the instance to make valgrind happy
bml: use a var for the exit code instead of an early return

We were skipping the close call and thus leaking memory.
buzzmachineloader: fix leaking the callbacks
bml: use the same ts code in info that we use in the logger