ESP8266: call MBED_ERROR if watchdog is triggered on modem

[VeijoPesonen]

Description

Driver should call MBED_ERROR instead of trying to recover from watchdog reset. This would make certain that modem issues wouldn't get hidden.

Issue request type

[ ] Question
[X] Enhancement
[ ] Bug

[ciarmcom]

Internal Jira reference: https://jira.arm.com/browse/MBOCUSTRIA-769

[kseverinkangas-zg]

Instead I would call MBED_ASSERT, because the wifi module can be recovered by using hard reset.

[VeijoPesonen]

Problem with MBED_ASSERT is that it's only effective with debug and development builds. I would saying failing as fast as possible is the best option here because we don't know the reason behind a watchdog reset and how often it might be occurring. If the device can't connect to a network it is better to see from the logs what is causing it in as early stage as possible.

[SeppoTakalo]

MBED_ERROR causes device to reboot, and is therefore the correct action to get device back into known state.

[VeijoPesonen]

PR #9456 implementing the change approved.