netifd: track when wdev setup fails

netifd: track when wdev setup fails

When netifd failed to load a valid configuration, after an invalid one,
it was not possible to setup the wireless device. This patch
aims to track this situation and behave acordingly, by keeping
track of failed setup without affecting autostart behavior. Also
block the restart of the wdev, when not applied.

Signed-off-by: Eduardo Abinader <eduardoabinader@gmail.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>