This change fixes the obvious race for a status_set() between
check_optional_interfaces() and assess_status() as the later calls the former
which calls status_set(), returns the status, which is then potentially set
again by the assess_status() function. This cleans up the code so that only a
single status_set() is performed when calling assess_status().
Change-Id: I05e071d635819c516ab76684842a25a9c2f81d83
Related-Bug:#1588462
0322be6cc6