Guard test pid/1 allows invalid Pid into spawned program

[Vlad Dumitrescu]

Hi,

I think there is no problem. LogStream is a process linked to the process that
runs test:test() - when test terminates, then LogStream gets killed too. This is
a result of having test:test() spawned: it no longer is there when hello runs.
In the successful cases, the process running test:test() is the shell, and it
remains alive.

regards,
Vlad