Modify kconsumerd thread and spawning function

In the kconsumerd thread, the one use case where the kconsumerd tells us
he's ready but we are unable to connect is now validate using the
kconsumerd_pid in the spawn_kconsumerd_thread function.

Also, we do not iterate over and over on the error socket anymore. Upon
receiving an error from the kconsumerd, this means that the daemon will
quit and thus the thread is no longer necessary.

Signed-off-by: David Goulet <david.goulet@polymtl.ca>