MEDIUM: listeners: remove the now unused ZOMBIE state
The zombie state is not used anymore by the listeners, because in the
last two cases where it was tested it couldn't match as it was covered
by the test on the process mask. Instead now the FD is either in the
LISTEN state or the INIT state. This also avoids forcing the listener
to be single-dimensional because actually belonging to another process
isn't totally exclusive with the other states, which explains some of
the difficulties requiring to check the proc_mask and the fd sometimes.
So let's get rid of it now not to be tempted to reuse it.
The doc on the listeners state was updated.
6 files changed
