RTOS not trapped in assertOSError while-loop

[KnockbackNemo]

When the assertOSError function fails and enters an infinite while-loop, the loop is only as high of a priority as the task that called it. As a result, higher priority tasks can still run, even if a lower priority task experienced an OS error.

This happens any time the OS error occurs in a task that isn't the highest priority. To trap the OS in the loop and force a complete shutdown, one option is to lock the scheduler inside _assertOSError.