Add check of sem_wait/rtems_semaphore_obtain in console  loop

**Is your feature request related to a problem? Please describe.**
Console loop could spin if the semaphore returns error.

**Describe the solution you'd like**
Check for real errors (not just interrupted), and exit loop if needed.

**Describe alternatives you've considered**
None.

**Additional context**
Mentioned in #667

**Requester Info**
Jacob Hageman - NASA/GSFC
