Incidentd: Fix switch break warnings

A few switches didn't have explicit breaks in them, which was causing
warnings. They were all benign, as the logic did not necessitate a
break. But this is will stop the warnings and perhaps prevent future
bugs.

Change-Id: Idb293a4896f4df8d3f11d748e0e716efc26bbd6a
Fixes: 119047812
Test: N/A